diff --git a/src/webui/api/synccontroller.cpp b/src/webui/api/synccontroller.cpp
index dac4fb316..cb8a038c0 100644
--- a/src/webui/api/synccontroller.cpp
+++ b/src/webui/api/synccontroller.cpp
@@ -445,6 +445,12 @@ void SyncController::maindataAction()
 
     data["categories"] = categories;
 
+    QVariantList tags;
+    for (const QString &tag : asConst(session->tags()))
+        tags << tag;
+
+    data["tags"] = tags;
+
     QVariantMap serverState = getTranserInfo();
     serverState[KEY_TRANSFER_FREESPACEONDISK] = getFreeDiskSpace();
     serverState[KEY_SYNC_MAINDATA_QUEUEING] = session->isQueueingSystemEnabled();
diff --git a/src/webui/api/torrentscontroller.cpp b/src/webui/api/torrentscontroller.cpp
index 35561b10e..0a965bf28 100644
--- a/src/webui/api/torrentscontroller.cpp
+++ b/src/webui/api/torrentscontroller.cpp
@@ -1041,3 +1041,67 @@ void TorrentsController::categoriesAction()
 
     setResult(categories);
 }
+
+void TorrentsController::addTagsAction()
+{
+    checkParams({"hashes", "tags"});
+
+    const QStringList hashes {params()["hashes"].split('|')};
+    const QStringList tags {params()["tags"].split(',', QString::SkipEmptyParts)};
+
+    for (const QString &tag : tags) {
+        const QString tagTrimmed {tag.trimmed()};
+        applyToTorrents(hashes, [&tagTrimmed](BitTorrent::TorrentHandle *const torrent)
+        {
+            torrent->addTag(tagTrimmed);
+        });
+    }
+}
+
+void TorrentsController::removeTagsAction()
+{
+    checkParams({"hashes"});
+
+    const QStringList hashes {params()["hashes"].split('|')};
+    const QStringList tags {params()["tags"].split(',', QString::SkipEmptyParts)};
+
+    for (const QString &tag : tags) {
+        const QString tagTrimmed {tag.trimmed()};
+        applyToTorrents(hashes, [&tagTrimmed](BitTorrent::TorrentHandle *const torrent)
+        {
+            torrent->removeTag(tagTrimmed);
+        });
+    }
+
+    if (tags.isEmpty()) {
+        applyToTorrents(hashes, [](BitTorrent::TorrentHandle *const torrent)
+        {
+            torrent->removeAllTags();
+        });
+    }
+}
+
+void TorrentsController::createTagsAction()
+{
+    checkParams({"tags"});
+
+    const QStringList tags {params()["tags"].split(',', QString::SkipEmptyParts)};
+
+    for (const QString &tag : tags)
+        BitTorrent::Session::instance()->addTag(tag.trimmed());
+}
+
+void TorrentsController::deleteTagsAction()
+{
+    checkParams({"tags"});
+
+    const QStringList tags {params()["tags"].split(',', QString::SkipEmptyParts)};
+    for (const QString &tag : tags)
+        BitTorrent::Session::instance()->removeTag(tag.trimmed());
+}
+
+void TorrentsController::tagsAction()
+{
+    const QStringList tags = BitTorrent::Session::instance()->tags().toList();
+    setResult(QJsonArray::fromStringList(tags));
+}
diff --git a/src/webui/api/torrentscontroller.h b/src/webui/api/torrentscontroller.h
index 2f467a22e..61bf4e14f 100644
--- a/src/webui/api/torrentscontroller.h
+++ b/src/webui/api/torrentscontroller.h
@@ -56,6 +56,11 @@ private slots:
     void editCategoryAction();
     void removeCategoriesAction();
     void categoriesAction();
+    void addTagsAction();
+    void removeTagsAction();
+    void createTagsAction();
+    void deleteTagsAction();
+    void tagsAction();
     void addAction();
     void deleteAction();
     void addTrackersAction();
diff --git a/src/webui/www/private/addtrackers.html b/src/webui/www/private/addtrackers.html
index 10b77dc1f..a482f3464 100644
--- a/src/webui/www/private/addtrackers.html
+++ b/src/webui/www/private/addtrackers.html
@@ -32,7 +32,7 @@
             $('trackersUrls').focus();
             $('addTrackersButton').addEvent('click', function(e) {
                 new Event(e).stop();
-                var hash = new URI().getData('hash');
+                const hash = new URI().getData('hash');
                 new Request({
                     url: 'api/v2/torrents/addTrackers',
                     method: 'post',
diff --git a/src/webui/www/private/confirmdeletion.html b/src/webui/www/private/confirmdeletion.html
index f078ccb47..34334ebd4 100644
--- a/src/webui/www/private/confirmdeletion.html
+++ b/src/webui/www/private/confirmdeletion.html
@@ -10,8 +10,8 @@
     <script>
         'use strict';
 
-        var hashes = new URI().getData('hashes').split('|');
         window.addEvent('domready', function() {
+            const hashes = new URI().getData('hashes').split('|');
             $('cancelBtn').focus();
             $('cancelBtn').addEvent('click', function(e) {
                 new Event(e).stop();
@@ -20,8 +20,8 @@
             $('confirmBtn').addEvent('click', function(e) {
                 parent.torrentsTable.deselectAll();
                 new Event(e).stop();
-                var cmd = 'api/v2/torrents/delete';
-                var deleteFiles = $('deleteFromDiskCB').get('checked');
+                const cmd = 'api/v2/torrents/delete';
+                const deleteFiles = $('deleteFromDiskCB').get('checked');
                 new Request({
                     url: cmd,
                     method: 'post',
diff --git a/src/webui/www/private/css/style.css b/src/webui/www/private/css/style.css
index 3200778ce..b625af7ab 100644
--- a/src/webui/www/private/css/style.css
+++ b/src/webui/www/private/css/style.css
@@ -258,6 +258,11 @@ a.propButton img {
     -ms-interpolation-mode: bicubic;
 }
 
+.contextMenu li input[type=checkbox] {
+    position: relative;
+    top: 3px;
+}
+
 /* Sliders */
 
 .slider {
diff --git a/src/webui/www/private/download.html b/src/webui/www/private/download.html
index b615f16b2..1699dbf50 100644
--- a/src/webui/www/private/download.html
+++ b/src/webui/www/private/download.html
@@ -140,9 +140,9 @@
     <script>
         'use strict';
 
-        var encodedUrls = new URI().getData('urls');
+        const encodedUrls = new URI().getData('urls');
         if (encodedUrls) {
-            var urls = [];
+            const urls = [];
             encodedUrls.split('|').each(function(url) {
                 urls.push(decodeURIComponent(url));
             });
@@ -151,7 +151,7 @@
                 $('urls').set('value', urls.join("\n"));
         }
 
-        var submitted = false;
+        let submitted = false;
 
         $('downloadForm').addEventListener("submit", function() {
             $('startTorrentHidden').value = $('startTorrent').checked ? 'false' : 'true';
diff --git a/src/webui/www/private/downloadlimit.html b/src/webui/www/private/downloadlimit.html
index 926af0824..57f3f8e97 100644
--- a/src/webui/www/private/downloadlimit.html
+++ b/src/webui/www/private/downloadlimit.html
@@ -24,9 +24,9 @@
         <script>
             'use strict';
 
-            var hashes = new URI().getData('hashes').split('|');
-            var setDlLimit = function() {
-                var limit = $("dllimitUpdatevalue").value.toInt() * 1024;
+            const hashes = new URI().getData('hashes').split('|');
+            const setDlLimit = function() {
+                const limit = $("dllimitUpdatevalue").value.toInt() * 1024;
                 if (hashes[0] == "global") {
                     new Request({
                         url: 'api/v2/transfer/setDownloadLimit',
diff --git a/src/webui/www/private/edittracker.html b/src/webui/www/private/edittracker.html
index 53cc2b861..4838680e5 100644
--- a/src/webui/www/private/edittracker.html
+++ b/src/webui/www/private/edittracker.html
@@ -29,17 +29,17 @@
                 }
             }).activate();
 
-            var currentUrl = new URI().getData('url');
+            const currentUrl = new URI().getData('url');
             if (!currentUrl)
                 return false;
 
-            var decodedUrl = decodeURIComponent(currentUrl);
+            const decodedUrl = decodeURIComponent(currentUrl);
             $('trackerUrl').value = decodedUrl;
             $('trackerUrl').focus();
 
             $('editTrackerButton').addEvent('click', function(e) {
                 new Event(e).stop();
-                var hash = new URI().getData('hash');
+                const hash = new URI().getData('hash');
                 new Request({
                     url: 'api/v2/torrents/editTracker',
                     method: 'post',
diff --git a/src/webui/www/private/filters.html b/src/webui/www/private/filters.html
index 112a20356..a438750d7 100644
--- a/src/webui/www/private/filters.html
+++ b/src/webui/www/private/filters.html
@@ -21,11 +21,18 @@
     <ul class="filterList" id="categoryFilterList">
     </ul>
 </div>
+<div class="filterWrapper">
+    <span class="filterTitle" onclick="toggleFilterDisplay('tag');">
+        <img src="images/qbt-theme/go-down.svg">QBT_TR(Tags)QBT_TR[CONTEXT=TransferListFiltersWidget]
+    </span>
+    <ul class="filterList" id="tagFilterList">
+    </ul>
+</div>
 
 <script>
     'use strict';
 
-    var categoriesFilterContextMenu = new CategoriesFilterContextMenu({
+    const categoriesFilterContextMenu = new CategoriesFilterContextMenu({
         targets: '.categoriesFilterContextMenuTarget',
         menu: 'categoriesFilterMenu',
         actions: {
@@ -60,9 +67,44 @@
         }
     });
 
+    const tagsFilterContextMenu = new TagsFilterContextMenu({
+        targets: '.tagsFilterContextMenuTarget',
+        menu: 'tagsFilterMenu',
+        actions: {
+            createTag: function(element, ref) {
+                createTagFN();
+            },
+            deleteTag: function(element, ref) {
+                removeTagFN(element.id);
+            },
+            deleteUnusedTags: function(element, ref) {
+                deleteUnusedTagsFN();
+            },
+            startTorrentsByTag: function(element, ref) {
+                startTorrentsByTagFN(element.id);
+            },
+            pauseTorrentsByTag: function(element, ref) {
+                pauseTorrentsByTagFN(element.id);
+            },
+            deleteTorrentsByTag: function(element, ref) {
+                deleteTorrentsByTagFN(element.id);
+            }
+        },
+        offsets: {
+            x: -15,
+            y: 2
+        },
+        onShow: function() {
+            this.options.element.firstChild.click();
+        }
+    });
+
     if (localStorage.getItem('filter_status_collapsed') === "true")
         toggleFilterDisplay('status');
 
     if (localStorage.getItem('filter_category_collapsed') === "true")
         toggleFilterDisplay('category');
+
+    if (localStorage.getItem('filter_tag_collapsed') === "true")
+        toggleFilterDisplay('tag');
 </script>
diff --git a/src/webui/www/private/index.html b/src/webui/www/private/index.html
index 0fd0e8076..89fc2c68e 100644
--- a/src/webui/www/private/index.html
+++ b/src/webui/www/private/index.html
@@ -132,6 +132,10 @@
             <a href="#Category" class="arrow-right"><img src="images/qbt-theme/view-categories.svg" alt="QBT_TR(Category)QBT_TR[CONTEXT=TransferListWidget]"/> QBT_TR(Category)QBT_TR[CONTEXT=TransferListWidget]</a>
             <ul id="contextCategoryList" class="scrollableMenu"></ul>
         </li>
+        <li>
+            <a href="#Tags" class="arrow-right"><img src="images/qbt-theme/view-categories.svg" alt="QBT_TR(Tags)QBT_TR[CONTEXT=TransferListWidget]"/> QBT_TR(Tags)QBT_TR[CONTEXT=TransferListWidget]</a>
+            <ul id="contextTagList" class="scrollableMenu"></ul>
+        </li>
         <li>
             <a href="#autoTorrentManagement"><img src="images/qbt-theme/checked.svg" alt="QBT_TR(Automatic Torrent Management)QBT_TR[CONTEXT=TransferListWidget]"/> QBT_TR(Automatic Torrent Management)QBT_TR[CONTEXT=TransferListWidget]</a>
         </li>
@@ -170,6 +174,14 @@
         <li><a href="#pauseTorrentsByCategory"><img src="images/qbt-theme/media-playback-pause.svg" alt="QBT_TR(Pause torrents)QBT_TR[CONTEXT=CategoryFilterWidget]"/> QBT_TR(Pause torrents)QBT_TR[CONTEXT=CategoryFilterWidget]</a></li>
         <li><a href="#deleteTorrentsByCategory"><img src="images/qbt-theme/edit-delete.svg" alt="QBT_TR(Delete torrents)QBT_TR[CONTEXT=CategoryFilterWidget]"/> QBT_TR(Delete torrents)QBT_TR[CONTEXT=CategoryFilterWidget]</a></li>
     </ul>
+    <ul id="tagsFilterMenu" class="contextMenu">
+        <li><a href="#createTag"><img src="images/qbt-theme/list-add.svg" alt="QBT_TR(Add tag...)QBT_TR[CONTEXT=TagFilterWidget]"/> QBT_TR(Add tag...)QBT_TR[CONTEXT=TagFilterWidget]</a></li>
+        <li><a href="#deleteTag"><img src="images/qbt-theme/list-remove.svg" alt="QBT_TR(Remove tag)QBT_TR[CONTEXT=TagFilterWidget]"/> QBT_TR(Remove tag)QBT_TR[CONTEXT=TagFilterWidget]</a></li>
+        <li><a href="#deleteUnusedTags"><img src="images/qbt-theme/list-remove.svg" alt="QBT_TR(Remove unused tags)QBT_TR[CONTEXT=TagFilterWidget]"/> QBT_TR(Remove unused tags)QBT_TR[CONTEXT=TagFilterWidget]</a></li>
+        <li class="separator"><a href="#startTorrentsByTag"><img src="images/qbt-theme/media-playback-start.svg" alt="QBT_TR(Resume torrents)QBT_TR[CONTEXT=TagFilterWidget]"/> QBT_TR(Resume torrents)QBT_TR[CONTEXT=TagFilterWidget]</a></li>
+        <li><a href="#pauseTorrentsByTag"><img src="images/qbt-theme/media-playback-pause.svg" alt="QBT_TR(Pause torrents)QBT_TR[CONTEXT=TagFilterWidget]"/> QBT_TR(Pause torrents)QBT_TR[CONTEXT=TagFilterWidget]</a></li>
+        <li><a href="#deleteTorrentsByTag"><img src="images/qbt-theme/edit-delete.svg" alt="QBT_TR(Delete torrents)QBT_TR[CONTEXT=TagFilterWidget]"/> QBT_TR(Delete torrents)QBT_TR[CONTEXT=TagFilterWidget]</a></li>
+    </ul>
     <ul id="torrentTrackersMenu" class="contextMenu">
         <li><a href="#AddTracker"><img src="images/qbt-theme/list-add.svg" alt="QBT_TR(Add a new tracker...)QBT_TR[CONTEXT=TrackerListWidget]"/> QBT_TR(Add a new tracker...)QBT_TR[CONTEXT=TrackerListWidget]</a></li>
         <li class="separator"><a href="#EditTracker"><img src="images/qbt-theme/document-edit.svg" alt="QBT_TR(Edit tracker URL...)QBT_TR[CONTEXT=TrackerListWidget]"/> QBT_TR(Edit tracker URL...)QBT_TR[CONTEXT=TrackerListWidget]</a></li>
diff --git a/src/webui/www/private/installsearchplugin.html b/src/webui/www/private/installsearchplugin.html
index c2391bab3..4dc6c631d 100644
--- a/src/webui/www/private/installsearchplugin.html
+++ b/src/webui/www/private/installsearchplugin.html
@@ -29,7 +29,7 @@
 <script>
     'use strict';
 
-    var initInstallSearchPlugin = function() {
+    this.initInstallSearchPlugin = function() {
         new Keyboard({
             defaultEventType: 'keydown',
             events: {
@@ -37,7 +37,7 @@
                     // accept enter key as a click
                     new Event(e).stop();
 
-                    var elem = e.event.srcElement;
+                    const elem = e.event.srcElement;
                     if ((elem.id === "newPluginPath") || (elem.id === "newPluginOk"))
                         newPluginOk();
                     else if (elem.id === "newPluginCancel")
@@ -49,8 +49,8 @@
         $('newPluginPath').select();
     };
 
-    var newPluginOk = function() {
-        var path = $("newPluginPath").get("value").trim();
+    this.newPluginOk = function() {
+        const path = $("newPluginPath").get("value").trim();
         if (path)
             new Request({
                 url: 'api/v2/search/installPlugin',
diff --git a/src/webui/www/private/newcategory.html b/src/webui/www/private/newcategory.html
index 04dd6e447..b2cf42d88 100644
--- a/src/webui/www/private/newcategory.html
+++ b/src/webui/www/private/newcategory.html
@@ -30,10 +30,10 @@
         }).activate();
 
         window.addEvent('domready', function() {
-            var uriAction = safeTrim(new URI().getData('action'));
-            var uriHashes = safeTrim(new URI().getData('hashes'));
-            var uriCategoryName = safeTrim(new URI().getData('categoryName'));
-            var uriSavePath = safeTrim(new URI().getData('savePath'));
+            const uriAction = safeTrim(new URI().getData('action'));
+            const uriHashes = safeTrim(new URI().getData('hashes'));
+            const uriCategoryName = safeTrim(new URI().getData('categoryName'));
+            const uriSavePath = safeTrim(new URI().getData('savePath'));
 
             if (uriAction === "edit") {
                 if (!uriCategoryName)
@@ -51,10 +51,10 @@
             $('categoryNameButton').addEvent('click', function(e) {
                 new Event(e).stop();
 
-                var savePath = $('savePath').value.trim();
-                var categoryName = $('categoryName').value.trim();
+                const savePath = $('savePath').value.trim();
+                const categoryName = $('categoryName').value.trim();
 
-                var verifyCategoryName = function(name) {
+                const verifyCategoryName = function(name) {
                     if ((name === null) || (name === ""))
                         return false;
                     if (name.match("^([^\\\\\\/]|[^\\\\\\/]([^\\\\\\/]|\\/(?=[^\\/]))*[^\\\\\\/])$") === null) {
diff --git a/src/webui/www/private/newtag.html b/src/webui/www/private/newtag.html
new file mode 100644
index 000000000..d1b7d4a3a
--- /dev/null
+++ b/src/webui/www/private/newtag.html
@@ -0,0 +1,105 @@
+<!DOCTYPE html>
+<html lang="${LANG}">
+
+<head>
+    <meta charset="UTF-8" />
+    <title>QBT_TR(Add Tags)QBT_TR[CONTEXT=TransferListWidget]</title>
+    <link rel="stylesheet" href="css/style.css?v=${CACHEID}" type="text/css" />
+    <script src="scripts/lib/mootools-1.2-core-yc.js"></script>
+    <script src="scripts/lib/mootools-1.2-more.js"></script>
+    <script src="scripts/misc.js?locale=${LANG}&v=${CACHEID}"></script>
+    <script>
+        'use strict';
+
+        new Keyboard({
+            defaultEventType: 'keydown',
+            events: {
+                'Enter': function(event) {
+                    $('tagNameButton').click();
+                    event.preventDefault();
+                },
+                'Escape': function(event) {
+                    window.parent.closeWindows();
+                    event.preventDefault();
+                },
+                'Esc': function(event) {
+                    window.parent.closeWindows();
+                    event.preventDefault();
+                }
+            }
+        }).activate();
+
+        window.addEvent('domready', function() {
+            const uriAction = safeTrim(new URI().getData('action'));
+            const uriHashes = safeTrim(new URI().getData('hashes'));
+
+            if (uriAction === 'create')
+                $('legendText').innerText = 'QBT_TR(Tag:)QBT_TR[CONTEXT=TagFilterWidget]';
+
+            $('tagName').focus();
+
+            $('tagNameButton').addEvent('click', function(e) {
+                new Event(e).stop();
+
+                const tagName = $('tagName').value.trim();
+
+                const verifyTagName = function(name) {
+                    if ((name === null) || (name === ""))
+                        return false;
+                    if (name.indexOf(",") >= 0) {
+                        alert("QBT_TR(Invalid tag name)QBT_TR[CONTEXT=TagFilterWidget]");
+                        return false;
+                    }
+                    return true;
+                };
+
+                switch (uriAction) {
+                    case "set":
+                        if (uriHashes === "")
+                            return;
+
+                        new Request({
+                            url: 'api/v2/torrents/addTags',
+                            method: 'post',
+                            data: {
+                                hashes: uriHashes,
+                                tags: tagName,
+                            },
+                            onComplete: function() {
+                                window.parent.closeWindows();
+                            }
+                        }).send();
+                        break;
+
+                    case "create":
+                        if (!verifyTagName(tagName))
+                            return;
+
+                        new Request({
+                            url: 'api/v2/torrents/createTags',
+                            method: 'post',
+                            data: {
+                                tags: tagName,
+                            },
+                            onComplete: function() {
+                                window.parent.closeWindows();
+                            }
+                        }).send();
+                        break;
+                }
+            });
+        });
+    </script>
+</head>
+
+<body>
+    <div style="padding: 10px 10px 0px 10px;">
+        <p id="legendText" style="font-weight: bold;">QBT_TR(Comma-separated tags:)QBT_TR[CONTEXT=TransferListWidget]</p>
+        <input type="text" id="tagName" value="" maxlength="100" style="width: 220px;" />
+        <div style="text-align: center; padding-top: 10px;">
+            <input type="button" value="QBT_TR(Add)QBT_TR[CONTEXT=HttpServer]" id="tagNameButton" />
+        </div>
+    </div>
+</body>
+
+</html>
diff --git a/src/webui/www/private/preferences_content.html b/src/webui/www/private/preferences_content.html
index 8d13e022e..2f89d79dc 100644
--- a/src/webui/www/private/preferences_content.html
+++ b/src/webui/www/private/preferences_content.html
@@ -1084,34 +1084,34 @@
     'use strict';
 
     // Downloads tab
-    var WatchedFoldersTable = new HtmlTable($("watched_folders_tab"));
+    this.WatchedFoldersTable = new HtmlTable($("watched_folders_tab"));
 
-    var updateTempDirEnabled = function() {
-        var isTempDirEnabled = $('temppath_checkbox').getProperty('checked');
+    this.updateTempDirEnabled = function() {
+        const isTempDirEnabled = $('temppath_checkbox').getProperty('checked');
         $('temppath_text').setProperty('disabled', !isTempDirEnabled);
     };
 
-    var addWatchFolder = function() {
-        var new_folder = $('new_watch_folder_txt').getProperty('value').trim();
+    this.addWatchFolder = function() {
+        const new_folder = $('new_watch_folder_txt').getProperty('value').trim();
         if (new_folder.length <= 0) return;
 
-        var new_other = $('new_watch_folder_other_txt').getProperty('value').trim();
+        const new_other = $('new_watch_folder_other_txt').getProperty('value').trim();
         if (new_other.length <= 0) return;
 
-        var new_select = $('new_watch_folder_select').getProperty('value').trim();
+        const new_select = $('new_watch_folder_select').getProperty('value').trim();
 
-        var i = $('watched_folders_tab').getChildren('tbody')[0].getChildren('tr').length;
+        const i = $('watched_folders_tab').getChildren('tbody')[0].getChildren('tr').length;
         pushWatchFolder(i, new_folder, new_select, new_other);
 
         // Clear fields
         $('new_watch_folder_txt').setProperty('value', '');
-        var elt = $('new_watch_folder_select');
+        const elt = $('new_watch_folder_select');
         elt.setProperty('value', 'watch_folder');
-        var text = elt.options[elt.selectedIndex].innerHTML;
+        const text = elt.options[elt.selectedIndex].innerHTML;
         $('new_watch_folder_other_txt').setProperty('value', text);
     };
 
-    var changeWatchFolderSelect = function(item) {
+    this.changeWatchFolderSelect = function(item) {
         if (item.value == "other") {
             item.nextElementSibling.hidden = false;
             item.nextElementSibling.value = 'QBT_TR(Type folder here)QBT_TR[CONTEXT=HttpServer]';
@@ -1119,15 +1119,15 @@
         }
         else {
             item.nextElementSibling.hidden = true;
-            var text = item.options[item.selectedIndex].innerHTML;
+            const text = item.options[item.selectedIndex].innerHTML;
             item.nextElementSibling.value = text;
         }
     };
 
-    var pushWatchFolder = function(pos, folder, sel, other) {
-        var myinput = "<input id='text_watch_" + pos + "' type='text' value='" + folder + "'>";
-        var disableInput = (sel != "other");
-        var mycb = "<div class='select-watched-folder-editable'>"
+    this.pushWatchFolder = function(pos, folder, sel, other) {
+        const myinput = "<input id='text_watch_" + pos + "' type='text' value='" + folder + "'>";
+        const disableInput = (sel != "other");
+        const mycb = "<div class='select-watched-folder-editable'>"
             + "<select id ='cb_watch_" + pos + "' onchange='changeWatchFolderSelect(this)'>"
             + "<option value='watch_folder'>QBT_TR(Monitored folder)QBT_TR[CONTEXT=ScanFoldersModel]</option>"
             + "<option value='default_folder'>QBT_TR(Default save location)QBT_TR[CONTEXT=ScanFoldersModel]</option>"
@@ -1138,20 +1138,20 @@
         WatchedFoldersTable.push([myinput, mycb]);
         $('cb_watch_' + pos).setProperty('value', sel);
         if (disableInput) {
-            var elt = $('cb_watch_' + pos);
+            const elt = $('cb_watch_' + pos);
             other = elt.options[elt.selectedIndex].innerHTML;
         }
         $('cb_watch_txt_' + pos).setProperty('value', other);
     };
 
-    var getWatchedFolders = function() {
-        var nb_folders = $("watched_folders_tab").getChildren("tbody")[0].getChildren("tr").length;
-        var folders = new Hash();
-        for (var i = 0; i < nb_folders; ++i) {
-            var fpath = $('text_watch_' + i).getProperty('value').trim();
+    this.getWatchedFolders = function() {
+        const nb_folders = $("watched_folders_tab").getChildren("tbody")[0].getChildren("tr").length;
+        const folders = new Hash();
+        for (let i = 0; i < nb_folders; ++i) {
+            const fpath = $('text_watch_' + i).getProperty('value').trim();
             if (fpath.length > 0) {
-                var other;
-                var sel = $('cb_watch_' + i).getProperty('value').trim();
+                let other;
+                const sel = $('cb_watch_' + i).getProperty('value').trim();
                 if (sel == "other") {
                     other = $('cb_watch_txt_' + i).getProperty('value').trim();
                 }
@@ -1164,18 +1164,18 @@
         return folders;
     };
 
-    var updateExportDirEnabled = function() {
-        var isExportDirEnabled = $('exportdir_checkbox').getProperty('checked');
+    this.updateExportDirEnabled = function() {
+        const isExportDirEnabled = $('exportdir_checkbox').getProperty('checked');
         $('exportdir_text').setProperty('disabled', !isExportDirEnabled);
     };
 
-    var updateExportDirFinEnabled = function() {
-        var isExportDirFinEnabled = $('exportdirfin_checkbox').getProperty('checked');
+    this.updateExportDirFinEnabled = function() {
+        const isExportDirFinEnabled = $('exportdirfin_checkbox').getProperty('checked');
         $('exportdirfin_text').setProperty('disabled', !isExportDirFinEnabled);
     };
 
-    var updateMailNotification = function() {
-        var isMailNotificationEnabled = $('mail_notification_checkbox').getProperty('checked');
+    this.updateMailNotification = function() {
+        const isMailNotificationEnabled = $('mail_notification_checkbox').getProperty('checked');
         $('src_email_txt').setProperty('disabled', !isMailNotificationEnabled);
         $('dest_email_txt').setProperty('disabled', !isMailNotificationEnabled);
         $('smtp_server_txt').setProperty('disabled', !isMailNotificationEnabled);
@@ -1188,47 +1188,47 @@
         }
     };
 
-    var updateMailAuthSettings = function() {
-        var isMailAuthEnabled = $('mail_auth_checkbox').getProperty('checked');
+    this.updateMailAuthSettings = function() {
+        const isMailAuthEnabled = $('mail_auth_checkbox').getProperty('checked');
         $('mail_username_text').setProperty('disabled', !isMailAuthEnabled);
         $('mail_password_text').setProperty('disabled', !isMailAuthEnabled);
     };
 
-    var updateAutoRun = function() {
-        var isAutoRunEnabled = $('autorun_checkbox').getProperty('checked');
+    this.updateAutoRun = function() {
+        const isAutoRunEnabled = $('autorun_checkbox').getProperty('checked');
         $('autorunProg_txt').setProperty('disabled', !isAutoRunEnabled);
     };
 
     // Connection tab
-    var updateMaxConnecEnabled = function() {
-        var isMaxConnecEnabled = $('max_connec_checkbox').getProperty('checked');
+    this.updateMaxConnecEnabled = function() {
+        const isMaxConnecEnabled = $('max_connec_checkbox').getProperty('checked');
         $('max_connec_value').setProperty('disabled', !isMaxConnecEnabled);
     };
 
-    var updateMaxConnecPerTorrentEnabled = function() {
-        var isMaxConnecPerTorrentEnabled = $('max_connec_per_torrent_checkbox').getProperty('checked');
+    this.updateMaxConnecPerTorrentEnabled = function() {
+        const isMaxConnecPerTorrentEnabled = $('max_connec_per_torrent_checkbox').getProperty('checked');
         $('max_connec_per_torrent_value').setProperty('disabled', !isMaxConnecPerTorrentEnabled);
     };
 
-    var updateMaxUploadsEnabled = function() {
-        var isMaxUploadsEnabled = $('max_uploads_checkbox').getProperty('checked');
+    this.updateMaxUploadsEnabled = function() {
+        const isMaxUploadsEnabled = $('max_uploads_checkbox').getProperty('checked');
         $('max_uploads_value').setProperty('disabled', !isMaxUploadsEnabled);
     };
 
-    var updateMaxUploadsPerTorrentEnabled = function() {
-        var isMaxUploadsPerTorrentEnabled = $('max_uploads_per_torrent_checkbox').getProperty('checked');
+    this.updateMaxUploadsPerTorrentEnabled = function() {
+        const isMaxUploadsPerTorrentEnabled = $('max_uploads_per_torrent_checkbox').getProperty('checked');
         $('max_uploads_per_torrent_value').setProperty('disabled', !isMaxUploadsPerTorrentEnabled);
     };
 
-    var updatePeerProxySettings = function() {
-        var isPeerProxyTypeSelected = $('peer_proxy_type_select').getProperty('value') != "none";
+    this.updatePeerProxySettings = function() {
+        const isPeerProxyTypeSelected = $('peer_proxy_type_select').getProperty('value') != "none";
         $('peer_proxy_host_text').setProperty('disabled', !isPeerProxyTypeSelected);
         $('peer_proxy_port_value').setProperty('disabled', !isPeerProxyTypeSelected);
         $('use_peer_proxy_checkbox').setProperty('disabled', !isPeerProxyTypeSelected);
         $('proxy_only_for_torrents_checkbox').setProperty('disabled', !isPeerProxyTypeSelected);
 
         if (isPeerProxyTypeSelected) {
-            var isPeerProxyTypeSocks5 = $('peer_proxy_type_select').getProperty('value') == "socks5";
+            const isPeerProxyTypeSocks5 = $('peer_proxy_type_select').getProperty('value') == "socks5";
             $('peer_proxy_auth_checkbox').setProperty('disabled', !isPeerProxyTypeSocks5);
 
             if (!isPeerProxyTypeSocks5) {
@@ -1243,22 +1243,22 @@
         }
     };
 
-    var updatePeerProxyAuthSettings = function() {
-        var isPeerProxyAuthEnabled = $('peer_proxy_auth_checkbox').getProperty('checked');
+    this.updatePeerProxyAuthSettings = function() {
+        const isPeerProxyAuthEnabled = $('peer_proxy_auth_checkbox').getProperty('checked');
         $('peer_proxy_username_text').setProperty('disabled', !isPeerProxyAuthEnabled);
         $('peer_proxy_password_text').setProperty('disabled', !isPeerProxyAuthEnabled);
     };
 
-    var updateFilterSettings = function() {
-        var isIPFilterEnabled = $('ipfilter_enabled_checkbox').getProperty('checked');
+    this.updateFilterSettings = function() {
+        const isIPFilterEnabled = $('ipfilter_enabled_checkbox').getProperty('checked');
         $('ipfilter_text').setProperty('disabled', !isIPFilterEnabled);
         $('ipfilter_trackers_checkbox').setProperty('disabled', !isIPFilterEnabled);
         $('banned_IPs_textarea').setProperty('disabled', !isIPFilterEnabled);
     };
 
     // Speed tab
-    var updateSchedulingEnabled = function() {
-        var isLimitSchedulingEnabled = $('limit_sheduling_checkbox').getProperty('checked');
+    this.updateSchedulingEnabled = function() {
+        const isLimitSchedulingEnabled = $('limit_sheduling_checkbox').getProperty('checked');
         $('schedule_from_hour').setProperty('disabled', !isLimitSchedulingEnabled);
         $('schedule_from_min').setProperty('disabled', !isLimitSchedulingEnabled);
         $('schedule_to_hour').setProperty('disabled', !isLimitSchedulingEnabled);
@@ -1267,8 +1267,8 @@
     };
 
     // Bittorrent tab
-    var updateQueueingSystem = function() {
-        var isQueueingEnabled = $('queueing_checkbox').getProperty('checked');
+    this.updateQueueingSystem = function() {
+        const isQueueingEnabled = $('queueing_checkbox').getProperty('checked');
         $('max_active_dl_value').setProperty('disabled', !isQueueingEnabled);
         $('max_active_up_value').setProperty('disabled', !isQueueingEnabled);
         $('max_active_to_value').setProperty('disabled', !isQueueingEnabled);
@@ -1276,59 +1276,59 @@
         updateSlowTorrentsSettings();
     };
 
-    var updateSlowTorrentsSettings = function() {
-        var isDontCountSlowTorrentsEnabled = (!$('dont_count_slow_torrents_checkbox').getProperty('disabled')) && $('dont_count_slow_torrents_checkbox').getProperty('checked');
+    this.updateSlowTorrentsSettings = function() {
+        const isDontCountSlowTorrentsEnabled = (!$('dont_count_slow_torrents_checkbox').getProperty('disabled')) && $('dont_count_slow_torrents_checkbox').getProperty('checked');
         $('dl_rate_threshold').setProperty('disabled', !isDontCountSlowTorrentsEnabled);
         $('ul_rate_threshold').setProperty('disabled', !isDontCountSlowTorrentsEnabled);
         $('torrent_inactive_timer').setProperty('disabled', !isDontCountSlowTorrentsEnabled);
     };
 
-    var updateMaxRatioTimeEnabled = function() {
-        var isMaxRatioEnabled = $('max_ratio_checkbox').getProperty('checked');
+    this.updateMaxRatioTimeEnabled = function() {
+        const isMaxRatioEnabled = $('max_ratio_checkbox').getProperty('checked');
         $('max_ratio_value').setProperty('disabled', !isMaxRatioEnabled);
 
-        var isMaxSeedingTimeEnabled = $('max_seeding_time_checkbox').getProperty('checked');
+        const isMaxSeedingTimeEnabled = $('max_seeding_time_checkbox').getProperty('checked');
         $('max_seeding_time_value').setProperty('disabled', !isMaxSeedingTimeEnabled);
 
         $('max_ratio_act').setProperty('disabled', !(isMaxRatioEnabled || isMaxSeedingTimeEnabled));
     };
 
-    var updateAddTrackersEnabled = function() {
-        var isAddTrackersEnabled = $('add_trackers_checkbox').getProperty('checked');
+    this.updateAddTrackersEnabled = function() {
+        const isAddTrackersEnabled = $('add_trackers_checkbox').getProperty('checked');
         $('add_trackers_textarea').setProperty('disabled', !isAddTrackersEnabled);
     };
 
     // Web UI tab
-    var updateHttpsSettings = function() {
-        var isUseHttpsEnabled = $('use_https_checkbox').getProperty('checked');
+    this.updateHttpsSettings = function() {
+        const isUseHttpsEnabled = $('use_https_checkbox').getProperty('checked');
         $('ssl_cert_text').setProperty('disabled', !isUseHttpsEnabled);
         $('ssl_key_text').setProperty('disabled', !isUseHttpsEnabled);
     };
 
-    var updateBypasssAuthSettings = function() {
-        var isBypassAuthSubnetWhitelistEnabled = $('bypass_auth_subnet_whitelist_checkbox').getProperty('checked');
+    this.updateBypasssAuthSettings = function() {
+        const isBypassAuthSubnetWhitelistEnabled = $('bypass_auth_subnet_whitelist_checkbox').getProperty('checked');
         $('bypass_auth_subnet_whitelist_textarea').setProperty('disabled', !isBypassAuthSubnetWhitelistEnabled);
     };
 
-    var updateAlternativeWebUISettings = function() {
-        var isUseAlternativeWebUIEnabled = $('use_alt_webui_checkbox').getProperty('checked');
+    this.updateAlternativeWebUISettings = function() {
+        const isUseAlternativeWebUIEnabled = $('use_alt_webui_checkbox').getProperty('checked');
         $('webui_files_location_textarea').setProperty('disabled', !isUseAlternativeWebUIEnabled);
     };
 
-    var updateHostHeaderValidationSettings = function() {
-        var isHostHeaderValidationEnabled = $('host_header_validation_checkbox').getProperty('checked');
+    this.updateHostHeaderValidationSettings = function() {
+        const isHostHeaderValidationEnabled = $('host_header_validation_checkbox').getProperty('checked');
         $('webui_domain_textarea').setProperty('disabled', !isHostHeaderValidationEnabled);
     };
 
-    var updateDynDnsSettings = function() {
-        var isDynDnsEnabled = $('use_dyndns_checkbox').getProperty('checked');
+    this.updateDynDnsSettings = function() {
+        const isDynDnsEnabled = $('use_dyndns_checkbox').getProperty('checked');
         $('dyndns_select').setProperty('disabled', !isDynDnsEnabled);
         $('dyndns_domain_text').setProperty('disabled', !isDynDnsEnabled);
         $('dyndns_username_text').setProperty('disabled', !isDynDnsEnabled);
         $('dyndns_password_text').setProperty('disabled', !isDynDnsEnabled);
     };
 
-    var registerDynDns = function() {
+    this.registerDynDns = function() {
         if ($('dyndns_select').getProperty('value').toInt() == 1) {
             window.open("http://www.no-ip.com/services/managed_dns/free_dynamic_dns.html", "NO-IP Registration");
         }
@@ -1337,22 +1337,22 @@
         }
     };
 
-    var generateRandomPort = function() {
-        var min = 1024;
-        var max = 65535;
-        var port = Math.floor(Math.random() * (max - min + 1) + min);
+    this.generateRandomPort = function() {
+        const min = 1024;
+        const max = 65535;
+        const port = Math.floor(Math.random() * (max - min + 1) + min);
         $('port_value').setProperty('value', port);
     };
 
-    var time_padding = function(val) {
-        var ret = val.toString();
+    this.time_padding = function(val) {
+        let ret = val.toString();
         if (ret.length == 1)
             ret = '0' + ret;
         return ret;
     };
 
     // Advanced Tab
-    var updateNetworkInterfaces = function(default_iface) {
+    this.updateNetworkInterfaces = function(default_iface) {
         const url = 'api/v2/app/networkInterfaceList';
         $('networkInterface').empty();
         new Request.JSON({
@@ -1374,7 +1374,7 @@
         }).send();
     };
 
-    var updateInterfaceAddresses = function(iface, default_addr) {
+    this.updateInterfaceAddresses = function(iface, default_addr) {
         const url = 'api/v2/app/networkInterfaceAddressList';
         $('optionalIPAddressToBind').empty();
         new Request.JSON({
@@ -1399,8 +1399,8 @@
         }).send();
     }
 
-    var loadPreferences = function() {
-        var url = 'api/v2/app/preferences';
+    this.loadPreferences = function() {
+        const url = 'api/v2/app/preferences';
         new Request.JSON({
             url: url,
             method: 'get',
@@ -1448,10 +1448,10 @@
                     updateExportDirFinEnabled();
 
                     // Automatically add torrents from
-                    var i = 0;
-                    for (var folder in pref.scan_dirs) {
-                        var sel;
-                        var other = "";
+                    let i = 0;
+                    for (const folder in pref.scan_dirs) {
+                        let sel;
+                        let other = "";
                         if (typeof pref.scan_dirs[folder] == "string") {
                             other = pref.scan_dirs[folder];
                             sel = "other";
@@ -1486,7 +1486,7 @@
                     $('random_port_checkbox').setProperty('checked', pref.random_port);
 
                     // Connections Limits
-                    var max_connec = pref.max_connec.toInt();
+                    const max_connec = pref.max_connec.toInt();
                     if (max_connec <= 0) {
                         $('max_connec_checkbox').setProperty('checked', false);
                         $('max_connec_value').setProperty('value', 500);
@@ -1496,7 +1496,7 @@
                         $('max_connec_value').setProperty('value', max_connec);
                     }
                     updateMaxConnecEnabled();
-                    var max_connec_per_torrent = pref.max_connec_per_torrent.toInt();
+                    const max_connec_per_torrent = pref.max_connec_per_torrent.toInt();
                     if (max_connec_per_torrent <= 0) {
                         $('max_connec_per_torrent_checkbox').setProperty('checked', false);
                         $('max_connec_per_torrent_value').setProperty('value', 100);
@@ -1506,7 +1506,7 @@
                         $('max_connec_per_torrent_value').setProperty('value', max_connec_per_torrent);
                     }
                     updateMaxConnecPerTorrentEnabled();
-                    var max_uploads = pref.max_uploads.toInt();
+                    const max_uploads = pref.max_uploads.toInt();
                     if (max_uploads <= 0) {
                         $('max_uploads_checkbox').setProperty('checked', false);
                         $('max_uploads_value').setProperty('value', 8);
@@ -1516,7 +1516,7 @@
                         $('max_uploads_value').setProperty('value', max_uploads);
                     }
                     updateMaxUploadsEnabled();
-                    var max_uploads_per_torrent = pref.max_uploads_per_torrent.toInt();
+                    const max_uploads_per_torrent = pref.max_uploads_per_torrent.toInt();
                     if (max_uploads_per_torrent <= 0) {
                         $('max_uploads_per_torrent_checkbox').setProperty('checked', false);
                         $('max_uploads_per_torrent_value').setProperty('value', 4);
@@ -1587,7 +1587,7 @@
                     $('dht_checkbox').setProperty('checked', pref.dht);
                     $('pex_checkbox').setProperty('checked', pref.pex);
                     $('lsd_checkbox').setProperty('checked', pref.lsd);
-                    var encryption = pref.encryption.toInt();
+                    const encryption = pref.encryption.toInt();
                     $('encryption_select').getChildren('option')[encryption].setAttribute('selected', '');
                     $('anonymous_mode_checkbox').setProperty('checked', pref.anonymous_mode);
 
@@ -1608,14 +1608,12 @@
                         $('max_ratio_value').setProperty('value', pref.max_ratio);
                     else
                         $('max_ratio_value').setProperty('value', 1);
-                    var max_ratio_act = pref.max_ratio_act.toInt();
-                    $('max_ratio_act').getChildren('option')[max_ratio_act].setAttribute('selected', '');
                     $('max_seeding_time_checkbox').setProperty('checked', pref.max_seeding_time_enabled);
                     if (pref.max_seeding_time_enabled)
                         $('max_seeding_time_value').setProperty('value', pref.max_seeding_time.toInt());
                     else
                         $('max_seeding_time_value').setProperty('value', 1440);
-                    var max_ratio_act = pref.max_ratio_act.toInt();
+                    const max_ratio_act = pref.max_ratio_act.toInt();
                     $('max_ratio_act').getChildren('option')[max_ratio_act].setAttribute('selected', '');
                     updateMaxRatioTimeEnabled();
 
@@ -1703,8 +1701,8 @@
         }).send();
     };
 
-    var applyPreferences = function() {
-        var settings = new Hash();
+    this.applyPreferences = function() {
+        const settings = new Hash();
         // Validate form data
         // Downloads tab
         // When adding a torrent
@@ -1751,7 +1749,7 @@
 
         // Connection tab
         // Listening Port
-        var listen_port = $('port_value').getProperty('value').toInt();
+        const listen_port = $('port_value').getProperty('value').toInt();
         if (isNaN(listen_port) || listen_port < 1 || listen_port > 65535) {
             alert("QBT_TR(The port used for incoming connections must be between 1 and 65535.)QBT_TR[CONTEXT=HttpServer]");
             return;
@@ -1761,7 +1759,7 @@
         settings.set('random_port', $('random_port_checkbox').getProperty('checked'));
 
         // Connections Limits
-        var max_connec = -1;
+        let max_connec = -1;
         if ($('max_connec_checkbox').getProperty('checked')) {
             max_connec = $('max_connec_value').getProperty('value').toInt();
             if (isNaN(max_connec) || max_connec <= 0) {
@@ -1770,7 +1768,7 @@
             }
         }
         settings.set('max_connec', max_connec);
-        var max_connec_per_torrent = -1;
+        let max_connec_per_torrent = -1;
         if ($('max_connec_per_torrent_checkbox').getProperty('checked')) {
             max_connec_per_torrent = $('max_connec_per_torrent_value').getProperty('value').toInt();
             if (isNaN(max_connec_per_torrent) || max_connec_per_torrent <= 0) {
@@ -1779,7 +1777,7 @@
             }
         }
         settings.set('max_connec_per_torrent', max_connec_per_torrent);
-        var max_uploads = -1;
+        let max_uploads = -1;
         if ($('max_uploads_checkbox').getProperty('checked')) {
             max_uploads = $('max_uploads_value').getProperty('value').toInt();
             if (isNaN(max_uploads) || max_uploads <= 0) {
@@ -1788,7 +1786,7 @@
             }
         }
         settings.set('max_uploads', max_uploads);
-        var max_uploads_per_torrent = -1;
+        let max_uploads_per_torrent = -1;
         if ($('max_uploads_per_torrent_checkbox').getProperty('checked')) {
             max_uploads_per_torrent = $('max_uploads_per_torrent_value').getProperty('value').toInt();
             if (isNaN(max_uploads_per_torrent) || max_uploads_per_torrent <= 0) {
@@ -1799,9 +1797,9 @@
         settings.set('max_uploads_per_torrent', max_uploads_per_torrent);
 
         // Proxy Server
-        var proxy_type_str = $('peer_proxy_type_select').getProperty('value');
-        var proxy_type = 0;
-        var proxy_auth_enabled = false;
+        const proxy_type_str = $('peer_proxy_type_select').getProperty('value');
+        let proxy_type = 0;
+        let proxy_auth_enabled = false;
         if (proxy_type_str == "socks5") {
             if ($('peer_proxy_auth_checkbox').getProperty('checked')) {
                 proxy_type = 4;
@@ -1844,14 +1842,14 @@
 
         // Speed tab
         // Global Rate Limits
-        var up_limit = $('up_limit_value').getProperty('value').toInt() * 1024;
+        const up_limit = $('up_limit_value').getProperty('value').toInt() * 1024;
         if (isNaN(up_limit) || up_limit < 0) {
             alert("QBT_TR(Global upload rate limit must be greater than 0 or disabled.)QBT_TR[CONTEXT=HttpServer]");
             return;
         }
         settings.set('up_limit', up_limit);
 
-        var dl_limit = $('dl_limit_value').getProperty('value').toInt() * 1024;
+        const dl_limit = $('dl_limit_value').getProperty('value').toInt() * 1024;
         if (isNaN(dl_limit) || dl_limit < 0) {
             alert("QBT_TR(Global download rate limit must be greater than 0 or disabled.)QBT_TR[CONTEXT=HttpServer]");
             return;
@@ -1859,14 +1857,14 @@
         settings.set('dl_limit', dl_limit);
 
         // Alternative Global Rate Limits
-        var alt_up_limit = $('alt_up_limit_value').getProperty('value').toInt() * 1024;
+        const alt_up_limit = $('alt_up_limit_value').getProperty('value').toInt() * 1024;
         if (isNaN(alt_up_limit) || alt_up_limit < 0) {
             alert("QBT_TR(Alternative upload rate limit must be greater than 0 or disabled.)QBT_TR[CONTEXT=HttpServer]");
             return;
         }
         settings.set('alt_up_limit', alt_up_limit);
 
-        var alt_dl_limit = $('alt_dl_limit_value').getProperty('value').toInt() * 1024;
+        const alt_dl_limit = $('alt_dl_limit_value').getProperty('value').toInt() * 1024;
         if (isNaN(alt_dl_limit) || alt_dl_limit < 0) {
             alert("QBT_TR(Alternative download rate limit must be greater than 0 or disabled.)QBT_TR[CONTEXT=HttpServer]");
             return;
@@ -1879,7 +1877,7 @@
         settings.set('limit_lan_peers', $('limit_lan_peers_checkbox').getProperty('checked'));
 
         // Scheduler
-        var scheduling_enabled = $('limit_sheduling_checkbox').getProperty('checked');
+        const scheduling_enabled = $('limit_sheduling_checkbox').getProperty('checked');
         settings.set('scheduler_enabled', scheduling_enabled);
         if (scheduling_enabled) {
             settings.set('schedule_from_hour', $('schedule_from_hour').getProperty('value').toInt());
@@ -1900,38 +1898,38 @@
         // Torrent Queueing
         settings.set('queueing_enabled', $('queueing_checkbox').getProperty('checked'));
         if ($('queueing_checkbox').getProperty('checked')) {
-            var max_active_downloads = $('max_active_dl_value').getProperty('value').toInt();
+            const max_active_downloads = $('max_active_dl_value').getProperty('value').toInt();
             if (isNaN(max_active_downloads) || max_active_downloads < -1) {
                 alert("QBT_TR(Maximum active downloads must be greater than -1.)QBT_TR[CONTEXT=HttpServer]");
                 return;
             }
             settings.set('max_active_downloads', max_active_downloads);
-            var max_active_uploads = $('max_active_up_value').getProperty('value').toInt();
+            const max_active_uploads = $('max_active_up_value').getProperty('value').toInt();
             if (isNaN(max_active_uploads) || max_active_uploads < -1) {
                 alert("QBT_TR(Maximum active uploads must be greater than -1.)QBT_TR[CONTEXT=HttpServer]");
                 return;
             }
             settings.set('max_active_uploads', max_active_uploads);
-            var max_active_torrents = $('max_active_to_value').getProperty('value').toInt();
+            const max_active_torrents = $('max_active_to_value').getProperty('value').toInt();
             if (isNaN(max_active_torrents) || max_active_torrents < -1) {
                 alert("QBT_TR(Maximum active torrents must be greater than -1.)QBT_TR[CONTEXT=HttpServer]");
                 return;
             }
             settings.set('max_active_torrents', max_active_torrents);
             settings.set('dont_count_slow_torrents', $('dont_count_slow_torrents_checkbox').getProperty('checked'));
-            var dl_rate_threshold = $('dl_rate_threshold').getProperty('value').toInt();
+            const dl_rate_threshold = $('dl_rate_threshold').getProperty('value').toInt();
             if (isNaN(dl_rate_threshold) || (dl_rate_threshold < 1)) {
                 alert("QBT_TR(Download rate threshold must be greater than 0.)QBT_TR[CONTEXT=HttpServer]");
                 return;
             }
             settings.set('slow_torrent_dl_rate_threshold', dl_rate_threshold);
-            var ul_rate_threshold = $('ul_rate_threshold').getProperty('value').toInt();
+            const ul_rate_threshold = $('ul_rate_threshold').getProperty('value').toInt();
             if (isNaN(ul_rate_threshold) || (ul_rate_threshold < 1)) {
                 alert("QBT_TR(Upload rate threshold must be greater than 0.)QBT_TR[CONTEXT=HttpServer]");
                 return;
             }
             settings.set('slow_torrent_ul_rate_threshold', ul_rate_threshold);
-            var torrent_inactive_timer = $('torrent_inactive_timer').getProperty('value').toInt();
+            const torrent_inactive_timer = $('torrent_inactive_timer').getProperty('value').toInt();
             if (isNaN(torrent_inactive_timer) || (torrent_inactive_timer < 1)) {
                 alert("QBT_TR(Torrent inactivity timer must be greater than 0.)QBT_TR[CONTEXT=HttpServer]");
                 return;
@@ -1940,7 +1938,7 @@
         }
 
         // Share Ratio Limiting
-        var max_ratio = -1;
+        let max_ratio = -1;
         if ($('max_ratio_checkbox').getProperty('checked')) {
             max_ratio = $('max_ratio_value').getProperty('value');
             if (isNaN(max_ratio) || max_ratio < 0 || max_ratio > 9998) {
@@ -1952,7 +1950,7 @@
         settings.set('max_ratio', max_ratio);
         settings.set('max_ratio_act', $('max_ratio_act').getProperty('value').toInt());
 
-        var max_seeding_time = -1;
+        let max_seeding_time = -1;
         if ($('max_seeding_time_checkbox').getProperty('checked')) {
             max_seeding_time = $('max_seeding_time_value').getProperty('value').toInt();
             if (isNaN(max_seeding_time) || max_seeding_time < 0 || max_seeding_time > 525600) {
@@ -1974,8 +1972,8 @@
 
         // HTTP Server
         settings.set('web_ui_domain_list', $('webui_domain_textarea').getProperty('value'));
-        var web_ui_address = $('webui_address_value').getProperty('value').toString();
-        var web_ui_port = $('webui_port_value').getProperty('value').toInt();
+        const web_ui_address = $('webui_address_value').getProperty('value').toString();
+        const web_ui_port = $('webui_port_value').getProperty('value').toInt();
         if (isNaN(web_ui_port) || web_ui_port < 1 || web_ui_port > 65535) {
             alert("QBT_TR(The port used for the Web UI must be between 1 and 65535.)QBT_TR[CONTEXT=HttpServer]");
             return;
@@ -1988,12 +1986,12 @@
         settings.set('web_ui_https_key_path', $('ssl_key_text').getProperty('value'));
 
         // Authentication
-        var web_ui_username = $('webui_username_text').getProperty('value');
+        const web_ui_username = $('webui_username_text').getProperty('value');
         if (web_ui_username.length < 3) {
             alert("QBT_TR(The Web UI username must be at least 3 characters long.)QBT_TR[CONTEXT=OptionsDialog]");
             return;
         }
-        var web_ui_password = $('webui_password_text').getProperty('value');
+        const web_ui_password = $('webui_password_text').getProperty('value');
         if ((0 < web_ui_password.length) && (web_ui_password.length < 6)) {
             alert("QBT_TR(The Web UI password must be at least 6 characters long.)QBT_TR[CONTEXT=OptionsDialog]");
             return;
@@ -2008,8 +2006,8 @@
         settings.set('web_ui_session_timeout', $('webUISessionTimeoutInput').getProperty('value'));
 
         // Use alternative Web UI
-        var alternative_webui_enabled = $('use_alt_webui_checkbox').getProperty('checked');
-        var webui_files_location_textarea = $('webui_files_location_textarea').getProperty('value');
+        const alternative_webui_enabled = $('use_alt_webui_checkbox').getProperty('checked');
+        const webui_files_location_textarea = $('webui_files_location_textarea').getProperty('value');
         if (alternative_webui_enabled && (webui_files_location_textarea.trim() === "")) {
             alert("QBT_TR(The alternative Web UI files location cannot be blank.)QBT_TR[CONTEXT=OptionsDialog]");
             return;
@@ -2064,7 +2062,7 @@
         settings.set('announce_ip', $('announceIP').getProperty('value'));
 
         // Send it to qBT
-        var json_str = JSON.encode(settings);
+        const json_str = JSON.encode(settings);
 
         new Request({
             url: 'api/v2/app/setPreferences',
diff --git a/src/webui/www/private/properties_content.html b/src/webui/www/private/properties_content.html
index b01f2737e..3e0370800 100644
--- a/src/webui/www/private/properties_content.html
+++ b/src/webui/www/private/properties_content.html
@@ -155,7 +155,7 @@
 <script>
     'use strict';
 
-    var selectedTab = $(getLocalStorageItem('selected_tab', 'PropGeneralLink'));
+    const selectedTab = $(getLocalStorageItem('selected_tab', 'PropGeneralLink'));
     if (selectedTab)
         selectedTab.click();
 </script>
diff --git a/src/webui/www/private/rename.html b/src/webui/www/private/rename.html
index bc507b06a..a4b92a56c 100644
--- a/src/webui/www/private/rename.html
+++ b/src/webui/www/private/rename.html
@@ -30,7 +30,7 @@
         }).activate();
 
         window.addEvent('domready', function() {
-            var name = new URI().getData('name');
+            const name = new URI().getData('name');
             // set text field to current value
             if (name)
                 $('rename').value = decodeURIComponent(name);
@@ -39,11 +39,11 @@
             $('renameButton').addEvent('click', function(e) {
                 new Event(e).stop();
                 // check field
-                var name = $('rename').value.trim();
+                const name = $('rename').value.trim();
                 if (name === null || name === "")
                     return false;
 
-                var hash = new URI().getData('hash');
+                const hash = new URI().getData('hash');
                 if (hash) {
                     new Request({
                         url: 'api/v2/torrents/rename',
diff --git a/src/webui/www/private/scripts/client.js b/src/webui/www/private/scripts/client.js
index b8bdf323b..f1dba3980 100644
--- a/src/webui/www/private/scripts/client.js
+++ b/src/webui/www/private/scripts/client.js
@@ -24,50 +24,63 @@
 
 'use strict';
 
-var torrentsTable = new TorrentsTable();
-var torrentTrackersTable = new TorrentTrackersTable();
-var torrentPeersTable = new TorrentPeersTable();
-var torrentFilesTable = new TorrentFilesTable();
-var searchResultsTable = new SearchResultsTable();
-var searchPluginsTable = new SearchPluginsTable();
+this.torrentsTable = new TorrentsTable();
+const torrentTrackersTable = new TorrentTrackersTable();
+const torrentPeersTable = new TorrentPeersTable();
+const torrentFilesTable = new TorrentFilesTable();
+const searchResultsTable = new SearchResultsTable();
+const searchPluginsTable = new SearchPluginsTable();
 
-var updatePropertiesPanel = function() {};
+let updatePropertiesPanel = function() {};
 
-var updateTorrentData = function() {};
-var updateTrackersData = function() {};
-var updateTorrentPeersData = function() {};
-var updateWebSeedsData = function() {};
-var updateTorrentFilesData = function() {};
+let updateTorrentData = function() {};
+let updateTrackersData = function() {};
+let updateTorrentPeersData = function() {};
+let updateWebSeedsData = function() {};
+let updateTorrentFilesData = function() {};
 
-var updateMainData = function() {};
-var alternativeSpeedLimits = false;
-var queueing_enabled = true;
-var serverSyncMainDataInterval = 1500;
-var customSyncMainDataInterval = null;
+this.updateMainData = function() {};
+let alternativeSpeedLimits = false;
+let queueing_enabled = true;
+let serverSyncMainDataInterval = 1500;
+let customSyncMainDataInterval = null;
 
-var clipboardEvent;
+let clipboardEvent;
 
-var CATEGORIES_ALL = 1;
-var CATEGORIES_UNCATEGORIZED = 2;
+const CATEGORIES_ALL = 1;
+const CATEGORIES_UNCATEGORIZED = 2;
 
-var category_list = {};
+let category_list = {};
 
-var selected_category = CATEGORIES_ALL;
-var setCategoryFilter = function() {};
+let selected_category = CATEGORIES_ALL;
+let setCategoryFilter = function() {};
 
-var selected_filter = getLocalStorageItem('selected_filter', 'all');
-var setFilter = function() {};
-var toggleFilterDisplay = function() {};
+const TAGS_ALL = 1;
+const TAGS_UNTAGGED = 2;
 
-var loadSelectedCategory = function() {
+let tagList = {};
+
+let selectedTag = TAGS_ALL;
+let setTagFilter = function() {};
+
+let selected_filter = getLocalStorageItem('selected_filter', 'all');
+let setFilter = function() {};
+let toggleFilterDisplay = function() {};
+
+const loadSelectedCategory = function() {
     selected_category = getLocalStorageItem('selected_category', CATEGORIES_ALL);
 };
 loadSelectedCategory();
 
+const loadSelectedTag = function() {
+    selectedTag = getLocalStorageItem('selected_tag', TAGS_ALL);
+};
+loadSelectedTag();
+
 function genHash(string) {
-    var hash = 0;
-    for (var i = 0; i < string.length; ++i) {
-        var c = string.charCodeAt(i);
+    let hash = 0;
+    for (let i = 0; i < string.length; ++i) {
+        const c = string.charCodeAt(i);
         hash = (c + hash * 31) | 0;
     }
     return hash;
@@ -98,9 +111,9 @@ const qbtVersion = function() {
 
 window.addEvent('load', function() {
 
-    var saveColumnSizes = function() {
-        var filters_width = $('Filters').getSize().x;
-        var properties_height_rel = $('propertiesPanel').getSize().y / Window.getSize().y;
+    const saveColumnSizes = function() {
+        const filters_width = $('Filters').getSize().x;
+        const properties_height_rel = $('propertiesPanel').getSize().y / Window.getSize().y;
         localStorage.setItem('filters_width', filters_width);
         localStorage.setItem('properties_height_rel', properties_height_rel);
     };
@@ -118,8 +131,8 @@ window.addEvent('load', function() {
     });*/
     MochaUI.Desktop.initialize();
 
-    var buildTransfersTab = function() {
-        var filt_w = localStorage.getItem('filters_width');
+    const buildTransfersTab = function() {
+        let filt_w = localStorage.getItem('filters_width');
         if ($defined(filt_w))
             filt_w = filt_w.toInt();
         else
@@ -138,7 +151,7 @@ window.addEvent('load', function() {
         });
     };
 
-    var buildSearchTab = function() {
+    const buildSearchTab = function() {
         new MochaUI.Column({
             id: 'searchTabColumn',
             placement: 'main',
@@ -161,6 +174,14 @@ window.addEvent('load', function() {
             updateMainData();
     };
 
+    setTagFilter = function(hash) {
+        selectedTag = hash.toString();
+        localStorage.setItem('selected_tag', selectedTag);
+        highlightSelectedTag();
+        if (torrentsTable.tableBody !== undefined)
+            updateMainData();
+    };
+
     setFilter = function(f) {
         // Visually Select the right filter
         $("all_filter").removeClass("selectedFilter");
@@ -181,11 +202,11 @@ window.addEvent('load', function() {
     };
 
     toggleFilterDisplay = function(filter) {
-        var element = filter + "FilterList";
+        const element = filter + "FilterList";
         localStorage.setItem('filter_' + filter + "_collapsed", !$(element).hasClass("invisible"));
         $(element).toggleClass("invisible")
-        var parent = $(element).getParent(".filterWrapper");
-        var toggleIcon = $(parent).getChildren(".filterTitle img");
+        const parent = $(element).getParent(".filterWrapper");
+        const toggleIcon = $(parent).getChildren(".filterTitle img");
         if (toggleIcon)
             toggleIcon[0].toggleClass("rotate");
     };
@@ -211,7 +232,7 @@ window.addEvent('load', function() {
     initializeWindows();
 
     // Show Top Toolbar is enabled by default
-    var showTopToolbar = true;
+    let showTopToolbar = true;
     if (localStorage.getItem('show_top_toolbar') !== null)
         showTopToolbar = localStorage.getItem('show_top_toolbar') == "true";
     if (!showTopToolbar) {
@@ -220,7 +241,7 @@ window.addEvent('load', function() {
     }
 
     // Show Status Bar is enabled by default
-    var showStatusBar = true;
+    let showStatusBar = true;
     if (localStorage.getItem('show_status_bar') !== null)
         showStatusBar = localStorage.getItem('show_status_bar') === "true";
     if (!showStatusBar) {
@@ -228,12 +249,12 @@ window.addEvent('load', function() {
         $('desktopFooterWrapper').addClass('invisible');
     }
 
-    var speedInTitle = localStorage.getItem('speed_in_browser_title_bar') == "true";
+    let speedInTitle = localStorage.getItem('speed_in_browser_title_bar') == "true";
     if (!speedInTitle)
         $('speedInBrowserTitleBarLink').firstChild.style.opacity = '0';
 
     // After showing/hiding the toolbar + status bar
-    var showSearchEngine = localStorage.getItem('show_search_engine') === "true";
+    let showSearchEngine = localStorage.getItem('show_search_engine') === "true";
     if (!showSearchEngine) {
         // uncheck menu option
         $('showSearchEngineLink').firstChild.style.opacity = '0';
@@ -244,13 +265,13 @@ window.addEvent('load', function() {
     // After Show Top Toolbar
     MochaUI.Desktop.setDesktopSize();
 
-    var syncMainDataLastResponseId = 0;
-    var serverState = {};
+    let syncMainDataLastResponseId = 0;
+    const serverState = {};
 
-    var removeTorrentFromCategoryList = function(hash) {
+    const removeTorrentFromCategoryList = function(hash) {
         if (hash === null || hash === "")
             return false;
-        var removed = false;
+        let removed = false;
         Object.each(category_list, function(category) {
             if (Object.contains(category.torrents, hash)) {
                 removed = true;
@@ -260,15 +281,15 @@ window.addEvent('load', function() {
         return removed;
     };
 
-    var addTorrentToCategoryList = function(torrent) {
-        var category = torrent['category'];
+    const addTorrentToCategoryList = function(torrent) {
+        const category = torrent['category'];
         if (typeof category === 'undefined')
             return false;
         if (category.length === 0) { // Empty category
             removeTorrentFromCategoryList(torrent['hash']);
             return true;
         }
-        var categoryHash = genHash(category);
+        const categoryHash = genHash(category);
         if (category_list[categoryHash] === null) // This should not happen
             category_list[categoryHash] = {
                 name: category,
@@ -282,11 +303,47 @@ window.addEvent('load', function() {
         return false;
     };
 
-    var updateFilter = function(filter, filterTitle) {
-        $(filter + '_filter').firstChild.childNodes[1].nodeValue = filterTitle.replace('%1', torrentsTable.getFilteredTorrentsNumber(filter, CATEGORIES_ALL));
+    const removeTorrentFromTagList = function(hash) {
+        if ((hash === null) || (hash === ""))
+            return false;
+
+        let removed = false;
+        for (const key in tagList) {
+            const tag = tagList[key];
+            if (Object.contains(tag.torrents, hash)) {
+                removed = true;
+                tag.torrents.splice(tag.torrents.indexOf(hash), 1);
+            }
+        }
+        return removed;
     };
 
-    var updateFiltersList = function() {
+    const addTorrentToTagList = function(torrent) {
+        if (torrent['tags'] === undefined) // Tags haven't changed
+            return false;
+
+        removeTorrentFromTagList(torrent['hash']);
+
+        if (torrent['tags'].length === 0) // No tags
+            return true;
+
+        const tags = torrent['tags'].split(',');
+        let added = false;
+        for (let i = 0; i < tags.length; ++i) {
+            const tagHash = genHash(tags[i].trim());
+            if (!Object.contains(tagList[tagHash].torrents, torrent['hash'])) {
+                added = true;
+                tagList[tagHash].torrents.push(torrent['hash']);
+            }
+        }
+        return added;
+    };
+
+    const updateFilter = function(filter, filterTitle) {
+        $(filter + '_filter').firstChild.childNodes[1].nodeValue = filterTitle.replace('%1', torrentsTable.getFilteredTorrentsNumber(filter, CATEGORIES_ALL, TAGS_ALL));
+    };
+
+    const updateFiltersList = function() {
         updateFilter('all', 'QBT_TR(All (%1))QBT_TR[CONTEXT=StatusFilterWidget]');
         updateFilter('downloading', 'QBT_TR(Downloading (%1))QBT_TR[CONTEXT=StatusFilterWidget]');
         updateFilter('seeding', 'QBT_TR(Seeding (%1))QBT_TR[CONTEXT=StatusFilterWidget]');
@@ -298,17 +355,17 @@ window.addEvent('load', function() {
         updateFilter('errored', 'QBT_TR(Errored (%1))QBT_TR[CONTEXT=StatusFilterWidget]');
     };
 
-    var updateCategoryList = function() {
-        var categoryList = $('categoryFilterList');
+    const updateCategoryList = function() {
+        const categoryList = $('categoryFilterList');
         if (!categoryList)
             return;
         categoryList.empty();
 
-        var create_link = function(hash, text, count) {
-            var html = '<a href="#" onclick="setCategoryFilter(' + hash + ');return false;">'
+        const create_link = function(hash, text, count) {
+            const html = '<a href="#" onclick="setCategoryFilter(' + hash + ');return false;">'
                 + '<img src="images/qbt-theme/inode-directory.svg"/>'
                 + escapeHtml(text) + ' (' + count + ')' + '</a>';
-            var el = new Element('li', {
+            const el = new Element('li', {
                 id: hash,
                 html: html
             });
@@ -316,8 +373,8 @@ window.addEvent('load', function() {
             return el;
         };
 
-        var all = torrentsTable.getRowIds().length;
-        var uncategorized = 0;
+        const all = torrentsTable.getRowIds().length;
+        let uncategorized = 0;
         Object.each(torrentsTable.rows, function(row) {
             if (row['full_data'].category.length === 0)
                 uncategorized += 1;
@@ -325,44 +382,98 @@ window.addEvent('load', function() {
         categoryList.appendChild(create_link(CATEGORIES_ALL, 'QBT_TR(All)QBT_TR[CONTEXT=CategoryFilterModel]', all));
         categoryList.appendChild(create_link(CATEGORIES_UNCATEGORIZED, 'QBT_TR(Uncategorized)QBT_TR[CONTEXT=CategoryFilterModel]', uncategorized));
 
-        var sortedCategories = [];
+        const sortedCategories = [];
         Object.each(category_list, function(category) {
             sortedCategories.push(category.name);
         });
         sortedCategories.sort();
 
         Object.each(sortedCategories, function(categoryName) {
-            var categoryHash = genHash(categoryName);
-            var categoryCount = category_list[categoryHash].torrents.length;
+            const categoryHash = genHash(categoryName);
+            const categoryCount = category_list[categoryHash].torrents.length;
             categoryList.appendChild(create_link(categoryHash, categoryName, categoryCount));
         });
 
         highlightSelectedCategory();
     };
 
-    var highlightSelectedCategory = function() {
-        var categoryList = $('categoryFilterList');
+    const highlightSelectedCategory = function() {
+        const categoryList = $('categoryFilterList');
         if (!categoryList)
             return;
-        var childrens = categoryList.childNodes;
-        for (var i = 0; i < childrens.length; ++i) {
-            if (childrens[i].id == selected_category)
-                childrens[i].className = "selectedFilter";
+        const children = categoryList.childNodes;
+        for (let i = 0; i < children.length; ++i) {
+            if (children[i].id == selected_category)
+                children[i].className = "selectedFilter";
             else
-                childrens[i].className = "";
+                children[i].className = "";
         }
     };
 
-    var syncMainDataTimer;
-    var syncMainData = function() {
-        var url = new URI('api/v2/sync/maindata');
+    const updateTagList = function() {
+        const tagFilterList = $('tagFilterList');
+        if (tagFilterList === null)
+            return;
+
+        while (tagFilterList.firstChild !== null)
+            tagFilterList.removeChild(tagFilterList.firstChild);
+
+        const createLink = function(hash, text, count) {
+            const html = '<a href="#" onclick="setTagFilter(' + hash + ');return false;">'
+                + '<img src="images/qbt-theme/inode-directory.svg"/>'
+                + escapeHtml(text) + ' (' + count + ')' + '</a>';
+            const el = new Element('li', {
+                id: hash,
+                html: html
+            });
+            tagsFilterContextMenu.addTarget(el);
+            return el;
+        };
+
+        const torrentsCount = torrentsTable.getRowIds().length;
+        let untagged = 0;
+        for (const key in torrentsTable.rows) {
+            if (torrentsTable.rows.hasOwnProperty(key) && torrentsTable.rows[key]['full_data'].tags.length === 0)
+                untagged += 1;
+        }
+        tagFilterList.appendChild(createLink(TAGS_ALL, 'QBT_TR(All)QBT_TR[CONTEXT=TagFilterModel]', torrentsCount));
+        tagFilterList.appendChild(createLink(TAGS_UNTAGGED, 'QBT_TR(Untagged)QBT_TR[CONTEXT=TagFilterModel]', untagged));
+
+        const sortedTags = [];
+        for (const key in tagList)
+            sortedTags.push(tagList[key].name);
+        sortedTags.sort();
+
+        for (let i = 0; i < sortedTags.length; ++i) {
+            const tagName = sortedTags[i];
+            const tagHash = genHash(tagName);
+            const tagCount = tagList[tagHash].torrents.length;
+            tagFilterList.appendChild(createLink(tagHash, tagName, tagCount));
+        }
+
+        highlightSelectedTag();
+    };
+
+    const highlightSelectedTag = function() {
+        const tagFilterList = $('tagFilterList');
+        if (!tagFilterList)
+            return;
+
+        const children = tagFilterList.childNodes;
+        for (let i = 0; i < children.length; ++i)
+            children[i].className = (children[i].id === selectedTag) ? "selectedFilter" : "";
+    };
+
+    let syncMainDataTimer;
+    const syncMainData = function() {
+        const url = new URI('api/v2/sync/maindata');
         url.setData('rid', syncMainDataLastResponseId);
         new Request.JSON({
             url: url,
             noCache: true,
             method: 'get',
             onFailure: function() {
-                var errorDiv = $('error_div');
+                const errorDiv = $('error_div');
                 if (errorDiv)
                     errorDiv.set('html', 'QBT_TR(qBittorrent client is not reachable)QBT_TR[CONTEXT=HttpServer]');
                 clearTimeout(syncMainDataTimer);
@@ -372,21 +483,23 @@ window.addEvent('load', function() {
                 $('error_div').set('html', '');
                 if (response) {
                     clearTimeout(torrentsFilterInputTimer);
-                    var torrentsTableSelectedRows;
-                    var update_categories = false;
-                    var full_update = (response['full_update'] === true);
+                    let torrentsTableSelectedRows;
+                    let update_categories = false;
+                    let updateTags = false;
+                    const full_update = (response['full_update'] === true);
                     if (full_update) {
                         torrentsTableSelectedRows = torrentsTable.selectedRowsIds();
                         torrentsTable.clear();
                         category_list = {};
+                        tagList = {};
                     }
                     if (response['rid']) {
                         syncMainDataLastResponseId = response['rid'];
                     }
                     if (response['categories']) {
-                        for (var key in response['categories']) {
-                            var category = response['categories'][key];
-                            var categoryHash = genHash(key);
+                        for (const key in response['categories']) {
+                            const category = response['categories'][key];
+                            const categoryHash = genHash(key);
                             if (category_list[categoryHash] !== undefined) {
                                 // only the save path can change for existing categories
                                 category_list[categoryHash].savePath = category.savePath;
@@ -403,14 +516,33 @@ window.addEvent('load', function() {
                     }
                     if (response['categories_removed']) {
                         response['categories_removed'].each(function(category) {
-                            var categoryHash = genHash(category);
+                            const categoryHash = genHash(category);
                             delete category_list[categoryHash];
                         });
                         update_categories = true;
                     }
+                    if (response['tags']) {
+                        for (const tag of response['tags']) {
+                            const tagHash = genHash(tag);
+                            if (!tagList[tagHash]) {
+                                tagList[tagHash] = {
+                                    name: tag,
+                                    torrents: []
+                                };
+                            }
+                        }
+                        updateTags = true;
+                    }
+                    if (response['tags_removed']) {
+                        for (let i = 0; i < response['tags_removed'].length; ++i) {
+                            const tagHash = genHash(response['tags_removed'][i]);
+                            delete tagList[tagHash];
+                        }
+                        updateTags = true;
+                    }
                     if (response['torrents']) {
-                        var updateTorrentList = false;
-                        for (var key in response['torrents']) {
+                        let updateTorrentList = false;
+                        for (const key in response['torrents']) {
                             response['torrents'][key]['hash'] = key;
                             response['torrents'][key]['rowId'] = key;
                             if (response['torrents'][key]['state'])
@@ -418,6 +550,8 @@ window.addEvent('load', function() {
                             torrentsTable.updateRowData(response['torrents'][key]);
                             if (addTorrentToCategoryList(response['torrents'][key]))
                                 update_categories = true;
+                            if (addTorrentToTagList(response['torrents'][key]))
+                                updateTags = true;
                             if (response['torrents'][key]['name'])
                                 updateTorrentList = true;
                         }
@@ -430,12 +564,14 @@ window.addEvent('load', function() {
                             torrentsTable.removeRow(hash);
                             removeTorrentFromCategoryList(hash);
                             update_categories = true; // Always to update All category
+                            removeTorrentFromTagList(hash);
+                            updateTags = true; // Always to update All tag
                         });
                     torrentsTable.updateTable(full_update);
                     torrentsTable.altRow();
                     if (response['server_state']) {
-                        var tmp = response['server_state'];
-                        for (var k in tmp)
+                        const tmp = response['server_state'];
+                        for (const k in tmp)
                             serverState[k] = tmp[k];
                         processServerState();
                     }
@@ -444,6 +580,10 @@ window.addEvent('load', function() {
                         updateCategoryList();
                         torrentsTableContextMenu.updateCategoriesSubMenu(category_list);
                     }
+                    if (updateTags) {
+                        updateTagList();
+                        torrentsTableContextMenu.updateTagsSubMenu(tagList);
+                    }
 
                     if (full_update)
                         // re-select previously selected rows
@@ -461,8 +601,8 @@ window.addEvent('load', function() {
         syncMainDataTimer = syncMainData.delay(100);
     };
 
-    var processServerState = function() {
-        var transfer_info = friendlyUnit(serverState.dl_info_speed, true);
+    const processServerState = function() {
+        let transfer_info = friendlyUnit(serverState.dl_info_speed, true);
         if (serverState.dl_rate_limit > 0)
             transfer_info += " [" + friendlyUnit(serverState.dl_rate_limit, true) + "]";
         transfer_info += " (" + friendlyUnit(serverState.dl_info_data, false) + ")";
@@ -534,7 +674,7 @@ window.addEvent('load', function() {
         serverSyncMainDataInterval = Math.max(serverState.refresh_interval, 500);
     };
 
-    var updateAltSpeedIcon = function(enabled) {
+    const updateAltSpeedIcon = function(enabled) {
         if (enabled)
             $('alternativeSpeedLimits').src = "images/slow.svg";
         else
@@ -628,7 +768,7 @@ window.addEvent('load', function() {
 
     // main window tabs
 
-    var showTransfersTab = function() {
+    const showTransfersTab = function() {
         $("filtersColumn").removeClass("invisible");
         $("filtersColumn_handle").removeClass("invisible");
         $("mainColumn").removeClass("invisible");
@@ -640,35 +780,35 @@ window.addEvent('load', function() {
         hideSearchTab();
     };
 
-    var hideTransfersTab = function() {
+    const hideTransfersTab = function() {
         $("filtersColumn").addClass("invisible");
         $("filtersColumn_handle").addClass("invisible");
         $("mainColumn").addClass("invisible");
         MochaUI.Desktop.resizePanels();
     };
 
-    var showSearchTab = function() {
+    const showSearchTab = function() {
         $("searchTabColumn").removeClass("invisible");
         customSyncMainDataInterval = 30000;
         hideTransfersTab();
     };
 
-    var hideSearchTab = function() {
+    const hideSearchTab = function() {
         $("searchTabColumn").addClass("invisible");
         MochaUI.Desktop.resizePanels();
     };
 
-    var addMainWindowTabsEventListener = function() {
+    const addMainWindowTabsEventListener = function() {
         $('transfersTabLink').addEvent('click', showTransfersTab);
         $('searchTabLink').addEvent('click', showSearchTab);
     };
 
-    var removeMainWindowTabsEventListener = function() {
+    const removeMainWindowTabsEventListener = function() {
         $('transfersTabLink').removeEvent('click', showTransfersTab);
         $('searchTabLink').removeEvent('click', showSearchTab);
     };
 
-    var addSearchPanel = function() {
+    const addSearchPanel = function() {
         new MochaUI.Panel({
             id: 'SearchPanel',
             title: 'Search',
@@ -707,7 +847,7 @@ window.addEvent('load', function() {
         onResize: saveColumnSizes,
         height: null
     });
-    var prop_h = localStorage.getItem('properties_height_rel');
+    let prop_h = localStorage.getItem('properties_height_rel');
     if ($defined(prop_h))
         prop_h = prop_h.toFloat() * Window.getSize().y;
     else
@@ -787,11 +927,11 @@ window.addEvent('load', function() {
         height: prop_h
     });
 
-    var prevTorrentsFilterValue;
-    var torrentsFilterInputTimer = null;
+    let prevTorrentsFilterValue;
+    let torrentsFilterInputTimer = null;
     // listen for changes to torrentsFilterInput
     $('torrentsFilterInput').addEvent('input', function() {
-        var value = $('torrentsFilterInput').get("value");
+        const value = $('torrentsFilterInput').get("value");
         if (value !== prevTorrentsFilterValue) {
             prevTorrentsFilterValue = value;
             clearTimeout(torrentsFilterInputTimer);
diff --git a/src/webui/www/private/scripts/contextmenu.js b/src/webui/www/private/scripts/contextmenu.js
index 899204c42..310f520f8 100644
--- a/src/webui/www/private/scripts/contextmenu.js
+++ b/src/webui/www/private/scripts/contextmenu.js
@@ -28,8 +28,8 @@
 
 'use strict';
 
-var lastShownContexMenu = null;
-var ContextMenu = new Class({
+let lastShownContextMenu = null;
+const ContextMenu = new Class({
     //implements
     Implements: [Options, Events],
 
@@ -87,7 +87,7 @@ var ContextMenu = new Class({
     adjustMenuPosition: function(e) {
         this.updateMenuItems();
 
-        var scrollableMenuMaxHeight = document.documentElement.clientHeight * 0.75;
+        const scrollableMenuMaxHeight = document.documentElement.clientHeight * 0.75;
 
         if (this.menu.hasClass('scrollableMenu'))
             this.menu.setStyle('max-height', scrollableMenuMaxHeight);
@@ -99,8 +99,8 @@ var ContextMenu = new Class({
         });
 
         // position the menu
-        var xPosMenu = e.page.x + this.options.offsets.x;
-        var yPosMenu = e.page.y + this.options.offsets.y;
+        let xPosMenu = e.page.x + this.options.offsets.x;
+        let yPosMenu = e.page.y + this.options.offsets.y;
         if (xPosMenu + this.menu.offsetWidth > document.documentElement.clientWidth)
             xPosMenu -= this.menu.offsetWidth;
         if (yPosMenu + this.menu.offsetHeight > document.documentElement.clientHeight)
@@ -117,16 +117,16 @@ var ContextMenu = new Class({
         });
 
         // position the sub-menu
-        var uls = this.menu.getElementsByTagName('ul');
-        for (var i = 0; i < uls.length; ++i) {
-            var ul = uls[i];
+        const uls = this.menu.getElementsByTagName('ul');
+        for (let i = 0; i < uls.length; ++i) {
+            const ul = uls[i];
             if (ul.hasClass('scrollableMenu'))
                 ul.setStyle('max-height', scrollableMenuMaxHeight);
-            var rectParent = ul.parentNode.getBoundingClientRect();
-            var xPosOrigin = rectParent.left;
-            var yPosOrigin = rectParent.bottom;
-            var xPos = xPosOrigin + rectParent.width - 1;
-            var yPos = yPosOrigin - rectParent.height - 1;
+            const rectParent = ul.parentNode.getBoundingClientRect();
+            const xPosOrigin = rectParent.left;
+            const yPosOrigin = rectParent.bottom;
+            let xPos = xPosOrigin + rectParent.width - 1;
+            let yPos = yPosOrigin - rectParent.height - 1;
             if (xPos + ul.offsetWidth > document.documentElement.clientWidth)
                 xPos -= (ul.offsetWidth + rectParent.width - 2);
             if (yPos + ul.offsetHeight > document.documentElement.clientHeight)
@@ -214,12 +214,12 @@ var ContextMenu = new Class({
 
     //show menu
     show: function(trigger) {
-        if (lastShownContexMenu && lastShownContexMenu != this)
-            lastShownContexMenu.hide();
+        if (lastShownContextMenu && lastShownContextMenu != this)
+            lastShownContextMenu.hide();
         this.fx.start(1);
         this.fireEvent('show');
         this.shown = true;
-        lastShownContexMenu = this;
+        lastShownContextMenu = this;
         return this;
     },
 
@@ -277,26 +277,27 @@ var ContextMenu = new Class({
     }
 });
 
-var TorrentsTableContextMenu = new Class({
+const TorrentsTableContextMenu = new Class({
     Extends: ContextMenu,
 
     updateMenuItems: function() {
-        var all_are_seq_dl = true;
-        var there_are_seq_dl = false;
-        var all_are_f_l_piece_prio = true;
-        var there_are_f_l_piece_prio = false;
-        var all_are_downloaded = true;
-        var all_are_paused = true;
-        var there_are_paused = false;
-        var all_are_force_start = true;
-        var there_are_force_start = false;
-        var all_are_super_seeding = true;
-        var all_are_auto_tmm = true;
-        var there_are_auto_tmm = false;
+        let all_are_seq_dl = true;
+        let there_are_seq_dl = false;
+        let all_are_f_l_piece_prio = true;
+        let there_are_f_l_piece_prio = false;
+        let all_are_downloaded = true;
+        let all_are_paused = true;
+        let there_are_paused = false;
+        let all_are_force_start = true;
+        let there_are_force_start = false;
+        let all_are_super_seeding = true;
+        let all_are_auto_tmm = true;
+        let there_are_auto_tmm = false;
+        const tagsSelectionState = Object.clone(tagList);
 
-        var h = torrentsTable.selectedRowsIds();
+        const h = torrentsTable.selectedRowsIds();
         h.each(function(item, index) {
-            var data = torrentsTable.rows.get(item).full_data;
+            const data = torrentsTable.rows.get(item).full_data;
 
             if (data['seq_dl'] !== true)
                 all_are_seq_dl = false;
@@ -327,14 +328,26 @@ var TorrentsTableContextMenu = new Class({
                 there_are_auto_tmm = true;
             else
                 all_are_auto_tmm = false;
+
+            const torrentTags = data['tags'].split(', ');
+            for (const key in tagsSelectionState) {
+                const tag = tagsSelectionState[key];
+                const tagExists = torrentTags.contains(tag.name);
+                if ((tag.checked !== undefined) && (tag.checked != tagExists))
+                    tag.indeterminate = true;
+                if (tag.checked === undefined)
+                    tag.checked = tagExists;
+                else
+                    tag.checked = tag.checked && tagExists;
+            }
         });
 
-        var show_seq_dl = true;
+        let show_seq_dl = true;
 
         if (!all_are_seq_dl && there_are_seq_dl)
             show_seq_dl = false;
 
-        var show_f_l_piece_prio = true;
+        let show_f_l_piece_prio = true;
 
         if (!all_are_f_l_piece_prio && there_are_f_l_piece_prio)
             show_f_l_piece_prio = false;
@@ -389,10 +402,17 @@ var TorrentsTableContextMenu = new Class({
             this.setItemChecked('autoTorrentManagement', all_are_auto_tmm);
         }
 
+        const contextTagList = $('contextTagList');
+        for (const tagHash in tagList) {
+            const checkbox = contextTagList.getElement('a[href=#Tag/' + tagHash + '] input[type=checkbox]');
+            const checkboxState = tagsSelectionState[tagHash];
+            checkbox.indeterminate = checkboxState.indeterminate;
+            checkbox.checked = checkboxState.checked;
+        }
     },
 
     updateCategoriesSubMenu: function(category_list) {
-        var categoryList = $('contextCategoryList');
+        const categoryList = $('contextCategoryList');
         categoryList.empty();
         categoryList.appendChild(new Element('li', {
             html: '<a href="javascript:torrentNewCategoryFN();"><img src="images/qbt-theme/list-add.svg" alt="QBT_TR(New...)QBT_TR[CONTEXT=TransferListWidget]"/> QBT_TR(New...)QBT_TR[CONTEXT=TransferListWidget]</a>'
@@ -401,16 +421,16 @@ var TorrentsTableContextMenu = new Class({
             html: '<a href="javascript:torrentSetCategoryFN(0);"><img src="images/qbt-theme/edit-clear.svg" alt="QBT_TR(Reset)QBT_TR[CONTEXT=TransferListWidget]"/> QBT_TR(Reset)QBT_TR[CONTEXT=TransferListWidget]</a>'
         }));
 
-        var sortedCategories = [];
+        const sortedCategories = [];
         Object.each(category_list, function(category) {
             sortedCategories.push(category.name);
         });
         sortedCategories.sort();
 
-        var first = true;
+        let first = true;
         Object.each(sortedCategories, function(categoryName) {
-            var categoryHash = genHash(categoryName);
-            var el = new Element('li', {
+            const categoryHash = genHash(categoryName);
+            const el = new Element('li', {
                 html: '<a href="javascript:torrentSetCategoryFN(\'' + categoryHash + '\');"><img src="images/qbt-theme/inode-directory.svg"/> ' + escapeHtml(categoryName) + '</a>'
             });
             if (first) {
@@ -419,13 +439,50 @@ var TorrentsTableContextMenu = new Class({
             }
             categoryList.appendChild(el);
         });
+    },
+
+    updateTagsSubMenu: function(tagList) {
+        const contextTagList = $('contextTagList');
+        while (contextTagList.firstChild !== null)
+            contextTagList.removeChild(contextTagList.firstChild);
+
+        contextTagList.appendChild(new Element('li', {
+            html: '<a href="javascript:torrentAddTagsFN();">'
+                + '<img src="images/qbt-theme/list-add.svg" alt="QBT_TR(Add...)QBT_TR[CONTEXT=TransferListWidget]"/>'
+                + ' QBT_TR(Add...)QBT_TR[CONTEXT=TransferListWidget]'
+                + '</a>'
+        }));
+        contextTagList.appendChild(new Element('li', {
+            html: '<a href="javascript:torrentRemoveAllTagsFN();">'
+                + '<img src="images/qbt-theme/edit-clear.svg" alt="QBT_TR(Remove All)QBT_TR[CONTEXT=TransferListWidget]"/>'
+                + ' QBT_TR(Remove All)QBT_TR[CONTEXT=TransferListWidget]'
+                + '</a>'
+        }));
+
+        const sortedTags = [];
+        for (const key in tagList)
+            sortedTags.push(tagList[key].name);
+        sortedTags.sort();
+
+        for (let i = 0; i < sortedTags.length; ++i) {
+            const tagName = sortedTags[i];
+            const tagHash = genHash(tagName);
+            const el = new Element('li', {
+                html: '<a href="#Tag/' + tagHash + '" onclick="event.preventDefault(); torrentSetTagsFN(\'' + tagHash + '\', !event.currentTarget.getElement(\'input[type=checkbox]\').checked);">'
+                    + '<input type="checkbox" onclick="this.checked = !this.checked;"> ' + escapeHtml(tagName)
+                    + '</a>'
+            });
+            if (i === 0)
+                el.addClass('separator');
+            contextTagList.appendChild(el);
+        }
     }
 });
 
-var CategoriesFilterContextMenu = new Class({
+const CategoriesFilterContextMenu = new Class({
     Extends: ContextMenu,
     updateMenuItems: function() {
-        var id = this.options.element.id;
+        const id = this.options.element.id;
         if ((id != CATEGORIES_ALL) && (id != CATEGORIES_UNCATEGORIZED)) {
             this.showItem('editCategory');
             this.showItem('deleteCategory');
@@ -437,13 +494,24 @@ var CategoriesFilterContextMenu = new Class({
     }
 });
 
-var SearchPluginsTableContextMenu = new Class({
+const TagsFilterContextMenu = new Class({
+    Extends: ContextMenu,
+    updateMenuItems: function() {
+        const id = this.options.element.id;
+        if ((id !== TAGS_ALL.toString()) && (id !== TAGS_UNTAGGED.toString()))
+            this.showItem('deleteTag');
+        else
+            this.hideItem('deleteTag');
+    }
+});
+
+const SearchPluginsTableContextMenu = new Class({
     Extends: ContextMenu,
 
     updateMenuItems: function() {
-        var enabledColumnIndex = function(text) {
-            var columns = $("searchPluginsTableFixedHeaderRow").getChildren("th");
-            for (var i = 0; i < columns.length; ++i)
+        const enabledColumnIndex = function(text) {
+            const columns = $("searchPluginsTableFixedHeaderRow").getChildren("th");
+            for (let i = 0; i < columns.length; ++i)
                 if (columns[i].get("html") === "Enabled")
                     return i;
         };
diff --git a/src/webui/www/private/scripts/download.js b/src/webui/www/private/scripts/download.js
index ed5d665a8..067105c4e 100644
--- a/src/webui/www/private/scripts/download.js
+++ b/src/webui/www/private/scripts/download.js
@@ -23,10 +23,10 @@
 
 'use strict';
 
-var categories = {};
-var defaultSavePath = "";
+let categories = {};
+let defaultSavePath = "";
 
-var getCategories = function() {
+const getCategories = function() {
     new Request.JSON({
         url: 'api/v2/torrents/categories',
         noCache: true,
@@ -34,9 +34,9 @@ var getCategories = function() {
         onSuccess: function(data) {
             if (data) {
                 categories = data;
-                for (var i in data) {
-                    var category = data[i];
-                    var option = new Element("option");
+                for (const i in data) {
+                    const category = data[i];
+                    const option = new Element("option");
                     option.set('value', category.name);
                     option.set('html', category.name);
                     $('categorySelect').appendChild(option);
@@ -46,7 +46,7 @@ var getCategories = function() {
     }).send();
 };
 
-var getPreferences = function() {
+const getPreferences = function() {
     new Request.JSON({
         url: 'api/v2/app/preferences',
         method: 'get',
@@ -74,7 +74,7 @@ var getPreferences = function() {
     }).send();
 };
 
-var changeCategorySelect = function(item) {
+const changeCategorySelect = function(item) {
     if (item.value == "\\other") {
         item.nextElementSibling.hidden = false;
         item.nextElementSibling.value = "";
@@ -85,13 +85,13 @@ var changeCategorySelect = function(item) {
     }
     else {
         item.nextElementSibling.hidden = true;
-        var text = item.options[item.selectedIndex].innerHTML;
+        const text = item.options[item.selectedIndex].innerHTML;
         item.nextElementSibling.value = text;
 
         if ($('autoTMM').selectedIndex == 1) {
-            var categoryName = item.value;
-            var category = categories[categoryName];
-            var savePath = defaultSavePath;
+            const categoryName = item.value;
+            const category = categories[categoryName];
+            let savePath = defaultSavePath;
             if (category !== undefined)
                 savePath = (category['savePath'] !== "") ? category['savePath'] : (defaultSavePath + categoryName);
             $('savepath').value = savePath;
@@ -99,13 +99,13 @@ var changeCategorySelect = function(item) {
     }
 };
 
-var changeTMM = function(item) {
+const changeTMM = function(item) {
     if (item.selectedIndex == 1) {
         $('savepath').disabled = true;
 
-        var categorySelect = $('categorySelect');
-        var categoryName = categorySelect.options[categorySelect.selectedIndex].value;
-        var category = categories[categoryName];
+        const categorySelect = $('categorySelect');
+        const categoryName = categorySelect.options[categorySelect.selectedIndex].value;
+        const category = categories[categoryName];
         $('savepath').value = (category === undefined) ? "" : category['savePath'];
     }
     else {
diff --git a/src/webui/www/private/scripts/dynamicTable.js b/src/webui/www/private/scripts/dynamicTable.js
index 0871c08eb..a3fc00421 100644
--- a/src/webui/www/private/scripts/dynamicTable.js
+++ b/src/webui/www/private/scripts/dynamicTable.js
@@ -33,10 +33,10 @@
 
 'use strict';
 
-var DynamicTableHeaderContextMenuClass = null;
-var ProgressColumnWidth = -1;
+let DynamicTableHeaderContextMenuClass = null;
+let ProgressColumnWidth = -1;
 
-var DynamicTable = new Class({
+const DynamicTable = new Class({
 
     initialize: function() {},
 
@@ -62,7 +62,7 @@ var DynamicTable = new Class({
     },
 
     setupCommonEvents: function() {
-        var scrollFn = function() {
+        const scrollFn = function() {
             $(this.dynamicTableFixedHeaderDivId).getElements('table')[0].style.left = -$(this.dynamicTableDivId).scrollLeft + 'px';
         }.bind(this);
 
@@ -70,14 +70,14 @@ var DynamicTable = new Class({
 
         // if the table exists within a panel
         if ($(this.dynamicTableDivId).getParent('.panel')) {
-            var resizeFn = function() {
-                var panel = $(this.dynamicTableDivId).getParent('.panel');
-                var h = panel.getBoundingClientRect().height - $(this.dynamicTableFixedHeaderDivId).getBoundingClientRect().height;
+            const resizeFn = function() {
+                const panel = $(this.dynamicTableDivId).getParent('.panel');
+                let h = panel.getBoundingClientRect().height - $(this.dynamicTableFixedHeaderDivId).getBoundingClientRect().height;
                 $(this.dynamicTableDivId).style.height = h + 'px';
 
                 // Workaround due to inaccurate calculation of elements heights by browser
 
-                var n = 2;
+                let n = 2;
 
                 while (panel.clientWidth != panel.offsetWidth && n > 0) { // is panel vertical scrollbar visible ?
                     --n;
@@ -94,8 +94,8 @@ var DynamicTable = new Class({
 
             // Workaround. Resize event is called not always (for example it isn't called when browser window changes it's size)
 
-            var checkResizeFn = function() {
-                var panel = $(this.dynamicTableDivId).getParent('.panel');
+            const checkResizeFn = function() {
+                const panel = $(this.dynamicTableDivId).getParent('.panel');
                 if (this.lastPanelHeight != panel.getBoundingClientRect().height) {
                     this.lastPanelHeight = panel.getBoundingClientRect().height;
                     panel.fireEvent('resize');
@@ -110,7 +110,7 @@ var DynamicTable = new Class({
         this.currentHeaderAction = '';
         this.canResize = false;
 
-        var resetElementBorderStyle = function(el, side) {
+        const resetElementBorderStyle = function(el, side) {
             if (side === 'left' || side !== 'right') {
                 el.setStyle('border-left-style', '');
                 el.setStyle('border-left-color', '');
@@ -123,9 +123,9 @@ var DynamicTable = new Class({
             }
         };
 
-        var mouseMoveFn = function(e) {
-            var brect = e.target.getBoundingClientRect();
-            var mouseXRelative = e.event.clientX - brect.left;
+        const mouseMoveFn = function(e) {
+            const brect = e.target.getBoundingClientRect();
+            const mouseXRelative = e.event.clientX - brect.left;
             if (this.currentHeaderAction === '') {
                 if (brect.width - mouseXRelative < 5) {
                     this.resizeTh = e.target;
@@ -143,9 +143,9 @@ var DynamicTable = new Class({
                 }
             }
             if (this.currentHeaderAction === 'drag') {
-                var previousVisibleSibling = e.target.getPrevious('[class=""]');
-                var borderChangeElement = previousVisibleSibling;
-                var changeBorderSide = 'right';
+                const previousVisibleSibling = e.target.getPrevious('[class=""]');
+                let borderChangeElement = previousVisibleSibling;
+                let changeBorderSide = 'right';
 
                 if (mouseXRelative > brect.width / 2) {
                     borderChangeElement = e.target;
@@ -178,18 +178,18 @@ var DynamicTable = new Class({
             this.lastClientX = e.event.clientX;
         }.bind(this);
 
-        var mouseOutFn = function(e) {
+        const mouseOutFn = function(e) {
             resetElementBorderStyle(e.target);
         }.bind(this);
 
-        var onBeforeStart = function(el) {
+        const onBeforeStart = function(el) {
             this.clickedTh = el;
             this.currentHeaderAction = 'start';
             this.dragMovement = false;
             this.dragStartX = this.lastClientX;
         }.bind(this);
 
-        var onStart = function(el, event) {
+        const onStart = function(el, event) {
             if (this.canResize) {
                 this.currentHeaderAction = 'resize';
                 this.startWidth = this.resizeTh.getStyle('width').toFloat();
@@ -200,9 +200,9 @@ var DynamicTable = new Class({
             }
         }.bind(this);
 
-        var onDrag = function(el, event) {
+        const onDrag = function(el, event) {
             if (this.currentHeaderAction === 'resize') {
-                var width = this.startWidth + (event.page.x - this.dragStartX);
+                let width = this.startWidth + (event.page.x - this.dragStartX);
                 if (width < 16)
                     width = 16;
                 this.columns[this.resizeTh.columnName].width = width;
@@ -210,16 +210,16 @@ var DynamicTable = new Class({
             }
         }.bind(this);
 
-        var onComplete = function(el, event) {
+        const onComplete = function(el, event) {
             resetElementBorderStyle(this.lastHoverTh);
             el.setStyle('background-color', '');
             if (this.currentHeaderAction === 'resize')
                 localStorage.setItem('column_' + this.resizeTh.columnName + '_width_' + this.dynamicTableDivId, this.columns[this.resizeTh.columnName].width);
             if ((this.currentHeaderAction === 'drag') && (el !== this.lastHoverTh)) {
                 this.saveColumnsOrder();
-                var val = localStorage.getItem('columns_order_' + this.dynamicTableDivId).split(',');
+                const val = localStorage.getItem('columns_order_' + this.dynamicTableDivId).split(',');
                 val.erase(el.columnName);
-                var pos = val.indexOf(this.lastHoverTh.columnName);
+                let pos = val.indexOf(this.lastHoverTh.columnName);
                 if (this.dropSide === 'right') ++pos;
                 val.splice(pos, 0, el.columnName);
                 localStorage.setItem('columns_order_' + this.dynamicTableDivId, val.join(','));
@@ -238,15 +238,15 @@ var DynamicTable = new Class({
             this.currentHeaderAction = '';
         }.bind(this);
 
-        var onCancel = function(el) {
+        const onCancel = function(el) {
             this.currentHeaderAction = '';
             this.setSortedColumn(el.columnName);
         }.bind(this);
 
-        var ths = this.fixedTableHeader.getElements('th');
+        const ths = this.fixedTableHeader.getElements('th');
 
-        for (var i = 0; i < ths.length; ++i) {
-            var th = ths[i];
+        for (let i = 0; i < ths.length; ++i) {
+            const th = ths[i];
             th.addEvent('mousemove', mouseMoveFn);
             th.addEvent('mouseout', mouseOutFn);
             th.makeResizable({
@@ -268,7 +268,7 @@ var DynamicTable = new Class({
             DynamicTableHeaderContextMenuClass = new Class({
                 Extends: ContextMenu,
                 updateMenuItems: function() {
-                    for (var i = 0; i < this.dynamicTable.columns.length; ++i) {
+                    for (let i = 0; i < this.dynamicTable.columns.length; ++i) {
                         if (this.dynamicTable.columns[i].caption === '')
                             continue;
                         if (this.dynamicTable.columns[i].visible !== '0')
@@ -290,28 +290,28 @@ var DynamicTable = new Class({
     setupHeaderMenu: function() {
         this.setupDynamicTableHeaderContextMenuClass();
 
-        var menuId = this.dynamicTableDivId + '_headerMenu';
+        const menuId = this.dynamicTableDivId + '_headerMenu';
 
-        var ul = new Element('ul', {
+        const ul = new Element('ul', {
             id: menuId,
             class: 'contextMenu scrollableMenu'
         });
 
-        var createLi = function(columnName, text) {
-            var html = '<a href="#' + columnName + '" ><img src="images/qbt-theme/checked.svg"/>' + escapeHtml(text) + '</a>';
+        const createLi = function(columnName, text) {
+            const html = '<a href="#' + columnName + '" ><img src="images/qbt-theme/checked.svg"/>' + escapeHtml(text) + '</a>';
             return new Element('li', {
                 html: html
             });
         };
 
-        var actions = {};
+        const actions = {};
 
-        var onMenuItemClicked = function(element, ref, action) {
+        const onMenuItemClicked = function(element, ref, action) {
             this.showColumn(action, this.columns[action].visible === '0');
         }.bind(this);
 
-        for (var i = 0; i < this.columns.length; ++i) {
-            var text = this.columns[i].caption;
+        for (let i = 0; i < this.columns.length; ++i) {
+            const text = this.columns[i].caption;
             if (text === '')
                 continue;
             ul.appendChild(createLi(this.columns[i].name, text));
@@ -336,7 +336,7 @@ var DynamicTable = new Class({
     initColumns: function() {},
 
     newColumn: function(name, style, caption, defaultWidth, defaultVisible) {
-        var column = {};
+        const column = {};
         column['name'] = name;
         column['title'] = name;
         column['visible'] = getLocalStorageItem('column_' + name + '_visible_' + this.dynamicTableDivId, defaultVisible ? '1' : '0');
@@ -371,25 +371,25 @@ var DynamicTable = new Class({
     },
 
     loadColumnsOrder: function() {
-        var columnsOrder = [];
-        var val = localStorage.getItem('columns_order_' + this.dynamicTableDivId);
+        const columnsOrder = [];
+        const val = localStorage.getItem('columns_order_' + this.dynamicTableDivId);
         if (val === null || val === undefined) return;
         val.split(',').forEach(function(v) {
             if ((v in this.columns) && (!columnsOrder.contains(v)))
                 columnsOrder.push(v);
         }.bind(this));
 
-        for (var i = 0; i < this.columns.length; ++i)
+        for (let i = 0; i < this.columns.length; ++i)
             if (!columnsOrder.contains(this.columns[i].name))
                 columnsOrder.push(this.columns[i].name);
 
-        for (i = 0; i < this.columns.length; ++i)
+        for (let i = 0; i < this.columns.length; ++i)
             this.columns[i] = this.columns[columnsOrder[i]];
     },
 
     saveColumnsOrder: function() {
-        var val = '';
-        for (var i = 0; i < this.columns.length; ++i) {
+        let val = '';
+        for (let i = 0; i < this.columns.length; ++i) {
             if (i > 0)
                 val += ',';
             val += this.columns[i].name;
@@ -403,10 +403,10 @@ var DynamicTable = new Class({
     },
 
     updateHeader: function(header) {
-        var ths = header.getElements('th');
+        const ths = header.getElements('th');
 
-        for (var i = 0; i < ths.length; ++i) {
-            var th = ths[i];
+        for (let i = 0; i < ths.length; ++i) {
+            const th = ths[i];
             th._this = this;
             th.setAttribute('title', this.columns[i].caption);
             th.innerHTML = this.columns[i].caption;
@@ -421,19 +421,19 @@ var DynamicTable = new Class({
     },
 
     getColumnPos: function(columnName) {
-        for (var i = 0; i < this.columns.length; ++i)
+        for (let i = 0; i < this.columns.length; ++i)
             if (this.columns[i].name == columnName)
                 return i;
         return -1;
     },
 
     updateColumn: function(columnName) {
-        var pos = this.getColumnPos(columnName);
-        var visible = ((this.columns[pos].visible != '0') && !this.columns[pos].force_hide);
-        var ths = this.hiddenTableHeader.getElements('th');
-        var fths = this.fixedTableHeader.getElements('th');
-        var trs = this.tableBody.getElements('tr');
-        var style = 'width: ' + this.columns[pos].width + 'px;' + this.columns[pos].style;
+        const pos = this.getColumnPos(columnName);
+        const visible = ((this.columns[pos].visible != '0') && !this.columns[pos].force_hide);
+        const ths = this.hiddenTableHeader.getElements('th');
+        const fths = this.fixedTableHeader.getElements('th');
+        const trs = this.tableBody.getElements('tr');
+        const style = 'width: ' + this.columns[pos].width + 'px;' + this.columns[pos].style;
 
         ths[pos].setAttribute('style', style);
         fths[pos].setAttribute('style', style);
@@ -441,13 +441,13 @@ var DynamicTable = new Class({
         if (visible) {
             ths[pos].removeClass('invisible');
             fths[pos].removeClass('invisible');
-            for (var i = 0; i < trs.length; ++i)
+            for (let i = 0; i < trs.length; ++i)
                 trs[i].getElements('td')[pos].removeClass('invisible');
         }
         else {
             ths[pos].addClass('invisible');
             fths[pos].addClass('invisible');
-            for (var j = 0; j < trs.length; ++j)
+            for (let j = 0; j < trs.length; ++j)
                 trs[j].getElements('td')[pos].addClass('invisible');
         }
         if (this.columns[pos].onResize !== null) {
@@ -455,13 +455,13 @@ var DynamicTable = new Class({
         }
     },
 
-    getSortedColunn: function() {
+    getSortedColumn: function() {
         return localStorage.getItem('sorted_column_' + this.dynamicTableDivId);
     },
 
     setSortedColumn: function(column) {
         if (column != this.sortedColumn) {
-            var oldColumn = this.sortedColumn;
+            const oldColumn = this.sortedColumn;
             this.sortedColumn = column;
             this.reverseSort = '0';
             this.setSortedColumnIcon(column, oldColumn, false);
@@ -477,14 +477,14 @@ var DynamicTable = new Class({
     },
 
     setSortedColumnIcon: function(newColumn, oldColumn, isReverse) {
-        var getCol = function(headerDivId, colName) {
-            var colElem = $$("#" + headerDivId + " .column_" + colName);
+        const getCol = function(headerDivId, colName) {
+            const colElem = $$("#" + headerDivId + " .column_" + colName);
             if (colElem.length == 1)
                 return colElem[0];
             return null;
         };
 
-        var colElem = getCol(this.dynamicTableFixedHeaderDivId, newColumn);
+        const colElem = getCol(this.dynamicTableFixedHeaderDivId, newColumn);
         if (colElem !== null) {
             colElem.addClass('sorted');
             if (isReverse)
@@ -492,7 +492,7 @@ var DynamicTable = new Class({
             else
                 colElem.removeClass('reverse');
         }
-        var oldColElem = getCol(this.dynamicTableFixedHeaderDivId, oldColumn);
+        const oldColElem = getCol(this.dynamicTableFixedHeaderDivId, oldColumn);
         if (oldColElem !== null) {
             oldColElem.removeClass('sorted');
             oldColElem.removeClass('reverse');
@@ -513,7 +513,7 @@ var DynamicTable = new Class({
         if (!MUI.ieLegacySupport)
             return;
 
-        var trs = this.tableBody.getElements('tr');
+        const trs = this.tableBody.getElements('tr');
         trs.each(function(el, i) {
             if (i % 2) {
                 el.addClass('alt');
@@ -527,9 +527,9 @@ var DynamicTable = new Class({
     selectAll: function() {
         this.deselectAll();
 
-        var trs = this.tableBody.getElements('tr');
-        for (var i = 0; i < trs.length; ++i) {
-            var tr = trs[i];
+        const trs = this.tableBody.getElements('tr');
+        for (let i = 0; i < trs.length; ++i) {
+            const tr = trs[i];
             this.selectedRows.push(tr.rowId);
             if (!tr.hasClass('selected'))
                 tr.addClass('selected');
@@ -559,8 +559,8 @@ var DynamicTable = new Class({
             return;
         }
 
-        var select = false;
-        var that = this;
+        let select = false;
+        const that = this;
         this.tableBody.getElements('tr').each(function(tr) {
             if ((tr.rowId == rowId1) || (tr.rowId == rowId2)) {
                 select = !select;
@@ -584,7 +584,7 @@ var DynamicTable = new Class({
     },
 
     setRowClass: function() {
-        var that = this;
+        const that = this;
         this.tableBody.getElements('tr').each(function(tr) {
             if (that.isRowSelected(tr.rowId))
                 tr.addClass('selected');
@@ -596,8 +596,8 @@ var DynamicTable = new Class({
     onSelectedRowChanged: function() {},
 
     updateRowData: function(data) {
-        var rowId = data['rowId'];
-        var row;
+        const rowId = data['rowId'];
+        let row;
 
         if (!this.rows.has(rowId)) {
             row = {};
@@ -610,23 +610,23 @@ var DynamicTable = new Class({
 
         row['data'] = data;
 
-        for (var x in data)
+        for (const x in data)
             row['full_data'][x] = data[x];
     },
 
     getFilteredAndSortedRows: function() {
-        var filteredRows = [];
+        const filteredRows = [];
 
-        var rows = this.rows.getValues();
+        const rows = this.rows.getValues();
 
-        for (var i = 0; i < rows.length; ++i) {
+        for (let i = 0; i < rows.length; ++i) {
             filteredRows.push(rows[i]);
             filteredRows[rows[i].rowId] = rows[i];
         }
 
         filteredRows.sort(function(row1, row2) {
-            var column = this.columns[this.sortedColumn];
-            var res = column.compareRows(row1, row2);
+            const column = this.columns[this.sortedColumn];
+            const res = column.compareRows(row1, row2);
             if (this.reverseSort == '0')
                 return res;
             else
@@ -636,8 +636,8 @@ var DynamicTable = new Class({
     },
 
     getTrByRowId: function(rowId) {
-        var trs = this.tableBody.getElements('tr');
-        for (var i = 0; i < trs.length; ++i)
+        const trs = this.tableBody.getElements('tr');
+        for (let i = 0; i < trs.length; ++i)
             if (trs[i].rowId == rowId)
                 return trs[i];
         return null;
@@ -647,26 +647,26 @@ var DynamicTable = new Class({
         if (fullUpdate === undefined)
             fullUpdate = false;
 
-        var rows = this.getFilteredAndSortedRows();
+        const rows = this.getFilteredAndSortedRows();
 
-        for (var i = 0; i < this.selectedRows.length; ++i)
+        for (let i = 0; i < this.selectedRows.length; ++i)
             if (!(this.selectedRows[i] in rows)) {
                 this.selectedRows.splice(i, 1);
                 --i;
             }
 
-        var trs = this.tableBody.getElements('tr');
+        const trs = this.tableBody.getElements('tr');
 
-        for (var rowPos = 0; rowPos < rows.length; ++rowPos) {
-            var rowId = rows[rowPos]['rowId'];
-            var tr_found = false;
-            for (var j = rowPos; j < trs.length; ++j)
+        for (let rowPos = 0; rowPos < rows.length; ++rowPos) {
+            const rowId = rows[rowPos]['rowId'];
+            let tr_found = false;
+            for (let j = rowPos; j < trs.length; ++j)
                 if (trs[j]['rowId'] == rowId) {
                     tr_found = true;
                     if (rowPos == j)
                         break;
                     trs[j].inject(trs[rowPos], 'before');
-                    var tmpTr = trs[j];
+                    const tmpTr = trs[j];
                     trs.splice(j, 1);
                     trs.splice(rowPos, 0, tmpTr);
                     break;
@@ -674,7 +674,7 @@ var DynamicTable = new Class({
             if (tr_found) // row already exists in the table
                 this.updateRow(trs[rowPos], fullUpdate);
             else { // else create a new row in the table
-                var tr = new Element('tr');
+                const tr = new Element('tr');
 
                 tr['rowId'] = rows[rowPos]['rowId'];
 
@@ -716,8 +716,8 @@ var DynamicTable = new Class({
 
                 this.setupTr(tr);
 
-                for (var k = 0; k < this.columns.length; ++k) {
-                    var td = new Element('td');
+                for (let k = 0; k < this.columns.length; ++k) {
+                    const td = new Element('td');
                     if ((this.columns[k].visible == '0') || this.columns[k].force_hide)
                         td.addClass('invisible');
                     td.injectInside(tr);
@@ -741,7 +741,7 @@ var DynamicTable = new Class({
             }
         }
 
-        rowPos = rows.length;
+        let rowPos = rows.length;
 
         while ((rowPos < trs.length) && (trs.length > 0)) {
             trs[trs.length - 1].dispose();
@@ -752,11 +752,11 @@ var DynamicTable = new Class({
     setupTr: function(tr) {},
 
     updateRow: function(tr, fullUpdate) {
-        var row = this.rows.get(tr.rowId);
-        var data = row[fullUpdate ? 'full_data' : 'data'];
+        const row = this.rows.get(tr.rowId);
+        const data = row[fullUpdate ? 'full_data' : 'data'];
 
-        var tds = tr.getElements('td');
-        for (var i = 0; i < this.columns.length; ++i) {
+        const tds = tr.getElements('td');
+        for (let i = 0; i < this.columns.length; ++i) {
             if (data.hasOwnProperty(this.columns[i].dataProperties[0]))
                 this.columns[i].updateTd(tds[i], row);
         }
@@ -765,7 +765,7 @@ var DynamicTable = new Class({
 
     removeRow: function(rowId) {
         this.selectedRows.erase(rowId);
-        var tr = this.getTrByRowId(rowId);
+        const tr = this.getTrByRowId(rowId);
         if (tr !== null) {
             tr.dispose();
             this.rows.erase(rowId);
@@ -777,7 +777,7 @@ var DynamicTable = new Class({
     clear: function() {
         this.deselectAll();
         this.rows.empty();
-        var trs = this.tableBody.getElements('tr');
+        const trs = this.tableBody.getElements('tr');
         while (trs.length > 0) {
             trs[trs.length - 1].dispose();
             trs.pop();
@@ -793,7 +793,7 @@ var DynamicTable = new Class({
     },
 });
 
-var TorrentsTable = new Class({
+const TorrentsTable = new Class({
     Extends: DynamicTable,
 
     initColumns: function() {
@@ -843,7 +843,7 @@ var TorrentsTable = new Class({
 
         // state_icon
         this.columns['state_icon'].updateTd = function(td, row) {
-            var state = this.getRowValue(row);
+            let state = this.getRowValue(row);
             // normalize states
             switch (state) {
                 case "forcedDL":
@@ -881,10 +881,10 @@ var TorrentsTable = new Class({
                     break; // do nothing
             }
 
-            var img_path = 'images/skin/' + state + '.svg';
+            const img_path = 'images/skin/' + state + '.svg';
 
             if (td.getChildren('img').length) {
-                var img = td.getChildren('img')[0];
+                const img = td.getChildren('img')[0];
                 if (img.src.indexOf(img_path) < 0) {
                     img.set('src', img_path);
                     img.set('title', state);
@@ -900,10 +900,10 @@ var TorrentsTable = new Class({
 
         // status
         this.columns['status'].updateTd = function(td, row) {
-            var state = this.getRowValue(row);
+            const state = this.getRowValue(row);
             if (!state) return;
 
-            var status;
+            let status;
             switch (state) {
                 case "downloading":
                     status = "QBT_TR(Downloading)QBT_TR[CONTEXT=TransferListDelegate]";
@@ -973,8 +973,8 @@ var TorrentsTable = new Class({
         };
 
         this.columns['priority'].compareRows = function(row1, row2) {
-            var row1_val = this.getRowValue(row1);
-            var row2_val = this.getRowValue(row2);
+            let row1_val = this.getRowValue(row1);
+            let row2_val = this.getRowValue(row2);
             if (row1_val < 1)
                 row1_val = 1000000;
             if (row2_val < 1)
@@ -1003,13 +1003,13 @@ var TorrentsTable = new Class({
 
         // progress
         this.columns['progress'].updateTd = function(td, row) {
-            var progress = this.getRowValue(row);
-            var progressFormated = (progress * 100).round(1);
+            const progress = this.getRowValue(row);
+            let progressFormated = (progress * 100).round(1);
             if (progressFormated == 100.0 && progress != 1.0)
                 progressFormated = 99.9;
 
             if (td.getChildren('div').length) {
-                var div = td.getChildren('div')[0];
+                const div = td.getChildren('div')[0];
                 if (td.resized) {
                     td.resized = false;
                     div.setWidth(ProgressColumnWidth - 5);
@@ -1028,11 +1028,11 @@ var TorrentsTable = new Class({
         };
 
         this.columns['progress'].onResize = function(columnName) {
-            var pos = this.getColumnPos(columnName);
-            var trs = this.tableBody.getElements('tr');
+            const pos = this.getColumnPos(columnName);
+            const trs = this.tableBody.getElements('tr');
             ProgressColumnWidth = -1;
-            for (var i = 0; i < trs.length; ++i) {
-                var td = trs[i].getElements('td')[pos];
+            for (let i = 0; i < trs.length; ++i) {
+                const td = trs[i].getElements('td')[pos];
                 if (ProgressColumnWidth < 0)
                     ProgressColumnWidth = td.offsetWidth;
                 td.resized = true;
@@ -1042,20 +1042,20 @@ var TorrentsTable = new Class({
 
         // num_seeds
         this.columns['num_seeds'].updateTd = function(td, row) {
-            var num_seeds = this.getRowValue(row, 0);
-            var num_complete = this.getRowValue(row, 1);
-            var html = num_seeds;
+            const num_seeds = this.getRowValue(row, 0);
+            const num_complete = this.getRowValue(row, 1);
+            let html = num_seeds;
             if (num_complete != -1)
                 html += ' (' + num_complete + ')';
             td.set('html', html);
             td.set('title', html);
         };
         this.columns['num_seeds'].compareRows = function(row1, row2) {
-            var num_seeds1 = this.getRowValue(row1, 0);
-            var num_complete1 = this.getRowValue(row1, 1);
+            const num_seeds1 = this.getRowValue(row1, 0);
+            const num_complete1 = this.getRowValue(row1, 1);
 
-            var num_seeds2 = this.getRowValue(row2, 0);
-            var num_complete2 = this.getRowValue(row2, 1);
+            const num_seeds2 = this.getRowValue(row2, 0);
+            const num_complete2 = this.getRowValue(row2, 1);
 
             if (num_complete1 < num_complete2)
                 return -1;
@@ -1091,8 +1091,8 @@ var TorrentsTable = new Class({
 
         // ratio
         this.columns['ratio'].updateTd = function(td, row) {
-            var ratio = this.getRowValue(row);
-            var html = null;
+            const ratio = this.getRowValue(row);
+            let html = null;
             if (ratio == -1)
                 html = '∞';
             else
@@ -1106,20 +1106,20 @@ var TorrentsTable = new Class({
 
         // added on
         this.columns['added_on'].updateTd = function(td, row) {
-            var date = new Date(this.getRowValue(row) * 1000).toLocaleString();
+            const date = new Date(this.getRowValue(row) * 1000).toLocaleString();
             td.set('html', date);
             td.set('title', date);
         };
 
         // completion_on
         this.columns['completion_on'].updateTd = function(td, row) {
-            var val = this.getRowValue(row);
+            const val = this.getRowValue(row);
             if ((val === 0xffffffff) || (val < 0)) {
                 td.set('html', '');
                 td.set('title', '');
             }
             else {
-                var date = new Date(this.getRowValue(row) * 1000).toLocaleString();
+                const date = new Date(this.getRowValue(row) * 1000).toLocaleString();
                 td.set('html', date);
                 td.set('title', date);
             }
@@ -1130,7 +1130,7 @@ var TorrentsTable = new Class({
 
         //  dl_limit, up_limit
         this.columns['dl_limit'].updateTd = function(td, row) {
-            var speed = this.getRowValue(row);
+            const speed = this.getRowValue(row);
             if (speed === 0) {
                 td.set('html', '∞');
                 td.set('title', '∞');
@@ -1163,7 +1163,7 @@ var TorrentsTable = new Class({
 
         // last_activity
         this.columns['last_activity'].updateTd = function(td, row) {
-            var val = this.getRowValue(row);
+            const val = this.getRowValue(row);
             if (val < 1) {
                 td.set('html', '∞');
                 td.set('title', '∞');
@@ -1183,11 +1183,11 @@ var TorrentsTable = new Class({
         };
     },
 
-    applyFilter: function(row, filterName, categoryHash, filterTerms) {
-        var state = row['full_data'].state;
-        var name = row['full_data'].name.toLowerCase();
-        var inactive = false;
-        var r;
+    applyFilter: function(row, filterName, categoryHash, tagHash, filterTerms) {
+        const state = row['full_data'].state;
+        const name = row['full_data'].name.toLowerCase();
+        let inactive = false;
+        let r;
 
         switch (filterName) {
             case 'downloading':
@@ -1227,7 +1227,7 @@ var TorrentsTable = new Class({
                 break;
         }
 
-        var categoryHashInt = parseInt(categoryHash);
+        const categoryHashInt = parseInt(categoryHash);
         if (!isNaN(categoryHashInt)) {
             switch (categoryHashInt) {
                 case CATEGORIES_ALL:
@@ -1242,8 +1242,30 @@ var TorrentsTable = new Class({
             }
         }
 
+        const tagHashInt = parseInt(tagHash);
+        const isNumber = !isNaN(tagHashInt);
+        if (isNumber) {
+            switch (tagHashInt) {
+                case TAGS_ALL:
+                    break;  // do nothing
+
+                case TAGS_UNTAGGED:
+                    if (row['full_data'].tags.length !== 0)
+                        return false;
+                    break;  // do nothing
+
+                default:
+                    let rowTags = row['full_data'].tags.split(', ');
+                    rowTags = rowTags.map(function(tag) {
+                        return genHash(tag);
+                    });
+                    if (!rowTags.contains(tagHashInt))
+                        return false;
+            }
+        }
+
         if (filterTerms) {
-            for (var i = 0; i < filterTerms.length; ++i) {
+            for (let i = 0; i < filterTerms.length; ++i) {
                 if (name.indexOf(filterTerms[i]) === -1)
                     return false;
             }
@@ -1252,43 +1274,43 @@ var TorrentsTable = new Class({
         return true;
     },
 
-    getFilteredTorrentsNumber: function(filterName, categoryHash) {
-        var cnt = 0;
-        var rows = this.rows.getValues();
+    getFilteredTorrentsNumber: function(filterName, categoryHash, tagHash) {
+        let cnt = 0;
+        const rows = this.rows.getValues();
 
-        for (var i = 0; i < rows.length; ++i)
-            if (this.applyFilter(rows[i], filterName, categoryHash, null)) ++cnt;
+        for (let i = 0; i < rows.length; ++i)
+            if (this.applyFilter(rows[i], filterName, categoryHash, tagHash, null)) ++cnt;
         return cnt;
     },
 
-    getFilteredTorrentsHashes: function(filterName, categoryHash) {
-        var rowsHashes = [];
-        var rows = this.rows.getValues();
+    getFilteredTorrentsHashes: function(filterName, categoryHash, tagHash) {
+        const rowsHashes = [];
+        const rows = this.rows.getValues();
 
-        for (var i = 0; i < rows.length; ++i)
-            if (this.applyFilter(rows[i], filterName, categoryHash, null))
+        for (let i = 0; i < rows.length; ++i)
+            if (this.applyFilter(rows[i], filterName, categoryHash, tagHash, null))
                 rowsHashes.push(rows[i]['rowId']);
 
         return rowsHashes;
     },
 
     getFilteredAndSortedRows: function() {
-        var filteredRows = [];
+        const filteredRows = [];
 
-        var rows = this.rows.getValues();
-        var filterText = $('torrentsFilterInput').value.trim().toLowerCase();
-        var filterTerms = (filterText.length > 0) ? filterText.split(" ") : null;
+        const rows = this.rows.getValues();
+        const filterText = $('torrentsFilterInput').value.trim().toLowerCase();
+        const filterTerms = (filterText.length > 0) ? filterText.split(" ") : null;
 
-        for (var i = 0; i < rows.length; ++i) {
-            if (this.applyFilter(rows[i], selected_filter, selected_category, filterTerms)) {
+        for (let i = 0; i < rows.length; ++i) {
+            if (this.applyFilter(rows[i], selected_filter, selected_category, selectedTag, filterTerms)) {
                 filteredRows.push(rows[i]);
                 filteredRows[rows[i].rowId] = rows[i];
             }
         }
 
         filteredRows.sort(function(row1, row2) {
-            var column = this.columns[this.sortedColumn];
-            var res = column.compareRows(row1, row2);
+            const column = this.columns[this.sortedColumn];
+            const res = column.compareRows(row1, row2);
             if (this.reverseSort == '0')
                 return res;
             else
@@ -1302,8 +1324,8 @@ var TorrentsTable = new Class({
             e.stop();
             this._this.deselectAll();
             this._this.selectRow(this.rowId);
-            var row = this._this.rows.get(this.rowId);
-            var state = row['full_data'].state;
+            const row = this._this.rows.get(this.rowId);
+            const state = row['full_data'].state;
             if (~state.indexOf('paused'))
                 startFN();
             else
@@ -1322,7 +1344,7 @@ var TorrentsTable = new Class({
     }
 });
 
-var TorrentPeersTable = new Class({
+const TorrentPeersTable = new Class({
     Extends: DynamicTable,
 
     initColumns: function() {
@@ -1350,8 +1372,8 @@ var TorrentPeersTable = new Class({
         // country
 
         this.columns['country'].updateTd = function(td, row) {
-            var country = this.getRowValue(row, 0);
-            var country_code = this.getRowValue(row, 1);
+            const country = this.getRowValue(row, 0);
+            const country_code = this.getRowValue(row, 1);
 
             if (!country_code) {
                 if (td.getChildren('img').length)
@@ -1359,10 +1381,10 @@ var TorrentPeersTable = new Class({
                 return;
             }
 
-            var img_path = 'images/flags/' + country_code + '.svg';
+            const img_path = 'images/flags/' + country_code + '.svg';
 
             if (td.getChildren('img').length) {
-                var img = td.getChildren('img')[0];
+                const img = td.getChildren('img')[0];
                 img.set('src', img_path);
                 img.set('class', 'flags');
                 img.set('alt', country);
@@ -1380,13 +1402,13 @@ var TorrentPeersTable = new Class({
         // ip
 
         this.columns['ip'].compareRows = function(row1, row2) {
-            var ip1 = this.getRowValue(row1);
-            var ip2 = this.getRowValue(row2);
+            const ip1 = this.getRowValue(row1);
+            const ip2 = this.getRowValue(row2);
 
-            var a = ip1.split(".");
-            var b = ip2.split(".");
+            const a = ip1.split(".");
+            const b = ip2.split(".");
 
-            for (var i = 0; i < 4; ++i) {
+            for (let i = 0; i < 4; ++i) {
                 if (a[i] != b[i])
                     return a[i] - b[i];
             }
@@ -1397,8 +1419,8 @@ var TorrentPeersTable = new Class({
         // progress, relevance
 
         this.columns['progress'].updateTd = function(td, row) {
-            var progress = this.getRowValue(row);
-            var progressFormated = (progress * 100).round(1);
+            const progress = this.getRowValue(row);
+            let progressFormated = (progress * 100).round(1);
             if (progressFormated == 100.0 && progress != 1.0)
                 progressFormated = 99.9;
             progressFormated += "%";
@@ -1411,7 +1433,7 @@ var TorrentPeersTable = new Class({
         // dl_speed, up_speed
 
         this.columns['dl_speed'].updateTd = function(td, row) {
-            var speed = this.getRowValue(row);
+            const speed = this.getRowValue(row);
             if (speed === 0) {
                 td.set('html', '');
                 td.set('title', '');
@@ -1452,7 +1474,7 @@ var TorrentPeersTable = new Class({
     }
 });
 
-var SearchResultsTable = new Class({
+const SearchResultsTable = new Class({
     Extends: DynamicTable,
 
     initColumns: function() {
@@ -1466,18 +1488,18 @@ var SearchResultsTable = new Class({
     },
 
     initColumnsFunctions: function() {
-        var displayText = function(td, row) {
-            var value = escapeHtml(this.getRowValue(row));
+        const displayText = function(td, row) {
+            const value = escapeHtml(this.getRowValue(row));
             td.set('html', value);
             td.set('title', value);
         }
-        var displaySize = function(td, row) {
+        const displaySize = function(td, row) {
             const size = friendlyUnit(this.getRowValue(row), false);
             td.set('html', size);
             td.set('title', size);
         }
-        var displayNum = function(td, row) {
-            var value = escapeHtml(this.getRowValue(row));
+        const displayNum = function(td, row) {
+            const value = escapeHtml(this.getRowValue(row));
             const formattedValue = (value === "-1") ? "Unknown" : value;
             td.set('html', formattedValue);
             td.set('title', formattedValue);
@@ -1491,9 +1513,9 @@ var SearchResultsTable = new Class({
     },
 
     getFilteredAndSortedRows: function() {
-        var containsAll = function(text, searchTerms) {
+        const containsAll = function(text, searchTerms) {
             text = text.toLowerCase();
-            for (var i = 0; i < searchTerms.length; ++i) {
+            for (let i = 0; i < searchTerms.length; ++i) {
                 if (text.indexOf(searchTerms[i].toLowerCase()) === -1)
                     return false;
             }
@@ -1501,12 +1523,12 @@ var SearchResultsTable = new Class({
             return true;
         };
 
-        var getSizeFilters = function() {
-            var minSize = (searchSizeFilter.min > 0.00) ? (searchSizeFilter.min * Math.pow(1024, searchSizeFilter.minUnit)) : 0.00;
-            var maxSize = (searchSizeFilter.max > 0.00) ? (searchSizeFilter.max * Math.pow(1024, searchSizeFilter.maxUnit)) : 0.00;
+        const getSizeFilters = function() {
+            let minSize = (searchSizeFilter.min > 0.00) ? (searchSizeFilter.min * Math.pow(1024, searchSizeFilter.minUnit)) : 0.00;
+            let maxSize = (searchSizeFilter.max > 0.00) ? (searchSizeFilter.max * Math.pow(1024, searchSizeFilter.maxUnit)) : 0.00;
 
             if ((minSize > maxSize) && (maxSize > 0.00)) {
-                var tmp = minSize;
+                const tmp = minSize;
                 minSize = maxSize;
                 maxSize = tmp;
             }
@@ -1517,12 +1539,12 @@ var SearchResultsTable = new Class({
             }
         };
 
-        var getSeedsFilters = function() {
-            var minSeeds = (searchSeedsFilter.min > 0) ? searchSeedsFilter.min : 0;
-            var maxSeeds = (searchSeedsFilter.max > 0) ? searchSeedsFilter.max : 0;
+        const getSeedsFilters = function() {
+            let minSeeds = (searchSeedsFilter.min > 0) ? searchSeedsFilter.min : 0;
+            let maxSeeds = (searchSeedsFilter.max > 0) ? searchSeedsFilter.max : 0;
 
             if ((minSeeds > maxSeeds) && (maxSeeds > 0)) {
-                var tmp = minSeeds;
+                const tmp = minSeeds;
                 minSeeds = maxSeeds;
                 maxSeeds = tmp;
             }
@@ -1533,17 +1555,17 @@ var SearchResultsTable = new Class({
             }
         };
 
-        var filteredRows = [];
-        var rows = this.rows.getValues();
-        var searchTerms = searchPattern.toLowerCase().split(" ");
-        var filterTerms = searchFilterPattern.toLowerCase().split(" ");
-        var sizeFilters = getSizeFilters();
-        var seedsFilters = getSeedsFilters();
-        var searchInTorrentName = $('searchInTorrentName').get('value') === "names";
+        let filteredRows = [];
+        const rows = this.rows.getValues();
+        const searchTerms = searchPattern.toLowerCase().split(" ");
+        const filterTerms = searchFilterPattern.toLowerCase().split(" ");
+        const sizeFilters = getSizeFilters();
+        const seedsFilters = getSeedsFilters();
+        const searchInTorrentName = $('searchInTorrentName').get('value') === "names";
 
         if (searchInTorrentName || filterTerms.length || (searchSizeFilter.min > 0.00) || (searchSizeFilter.max > 0.00)) {
-            for (var i = 0; i < rows.length; ++i) {
-                var row = rows[i];
+            for (let i = 0; i < rows.length; ++i) {
+                const row = rows[i];
 
                 if (searchInTorrentName && !containsAll(row.full_data.fileName, searchTerms)) continue;
                 if (filterTerms.length && !containsAll(row.full_data.fileName, filterTerms)) continue;
@@ -1560,8 +1582,8 @@ var SearchResultsTable = new Class({
         }
 
         filteredRows.sort(function(row1, row2) {
-            var column = this.columns[this.sortedColumn];
-            var res = column.compareRows(row1, row2);
+            const column = this.columns[this.sortedColumn];
+            const res = column.compareRows(row1, row2);
             if (this.reverseSort == '0')
                 return res;
             else
@@ -1576,7 +1598,7 @@ var SearchResultsTable = new Class({
     }
 });
 
-var SearchPluginsTable = new Class({
+const SearchPluginsTable = new Class({
     Extends: DynamicTable,
 
     initColumns: function() {
@@ -1589,7 +1611,7 @@ var SearchPluginsTable = new Class({
     },
 
     initColumnsFunctions: function() {
-        var displayText = function(td, row) {
+        const displayText = function(td, row) {
             const value = escapeHtml(this.getRowValue(row));
             td.set('html', value);
             td.set('title', value);
@@ -1599,7 +1621,7 @@ var SearchPluginsTable = new Class({
         this.columns['version'].updateTd = displayText;
         this.columns['url'].updateTd = displayText;
         this.columns['enabled'].updateTd = function(td, row) {
-            var value = this.getRowValue(row);
+            const value = this.getRowValue(row);
             if (value) {
                 td.set('html', "Yes");
                 td.set('title', "Yes");
@@ -1620,7 +1642,7 @@ var SearchPluginsTable = new Class({
     }
 });
 
-var TorrentTrackersTable = new Class({
+const TorrentTrackersTable = new Class({
     Extends: DynamicTable,
 
     initColumns: function() {
@@ -1635,7 +1657,7 @@ var TorrentTrackersTable = new Class({
     },
 });
 
-var TorrentFilesTable = new Class({
+const TorrentFilesTable = new Class({
     Extends: DynamicTable,
 
     initColumns: function() {
@@ -1651,26 +1673,26 @@ var TorrentFilesTable = new Class({
     },
 
     initColumnsFunctions: function() {
-        var displaySize = function(td, row) {
+        const displaySize = function(td, row) {
             const size = friendlyUnit(this.getRowValue(row), false);
             td.set('html', size);
             td.set('title', size);
         }
-        var displayPercentage = function(td, row) {
+        const displayPercentage = function(td, row) {
             const value = friendlyPercentage(this.getRowValue(row));
             td.set('html', value);
             td.set('title', value);
         };
 
         this.columns['checked'].updateTd = function(td, row) {
-            var id = row.rowId;
-            var value = this.getRowValue(row);
+            const id = row.rowId;
+            const value = this.getRowValue(row);
 
             if (isDownloadCheckboxExists(id)) {
                 updateDownloadCheckbox(id, value);
             }
             else {
-                var treeImg = new Element('img', {
+                const treeImg = new Element('img', {
                     src: 'images/L.gif',
                     style: 'margin-bottom: -2px'
                 });
@@ -1681,10 +1703,10 @@ var TorrentFilesTable = new Class({
         this.columns['size'].updateTd = displaySize;
 
         this.columns['progress'].updateTd = function(td, row) {
-            var id = row.rowId;
-            var value = this.getRowValue(row);
+            const id = row.rowId;
+            const value = this.getRowValue(row);
 
-            var progressBar = $('pbf_' + id);
+            const progressBar = $('pbf_' + id);
             if (progressBar === null) {
                 td.adopt(new ProgressBar(value.toFloat(), {
                     'id': 'pbf_' + id,
@@ -1697,8 +1719,8 @@ var TorrentFilesTable = new Class({
         };
 
         this.columns['priority'].updateTd = function(td, row) {
-            var id = row.rowId;
-            var value = this.getRowValue(row);
+            const id = row.rowId;
+            const value = this.getRowValue(row);
 
             if (isPriorityComboExists(id))
                 updatePriorityCombo(id, value);
diff --git a/src/webui/www/private/scripts/misc.js b/src/webui/www/private/scripts/misc.js
index 212b663e1..537b7c908 100644
--- a/src/webui/www/private/scripts/misc.js
+++ b/src/webui/www/private/scripts/misc.js
@@ -32,7 +32,7 @@
  * JS counterpart of the function in src/misc.cpp
  */
 function friendlyUnit(value, isSpeed) {
-    var units = [
+    const units = [
         "QBT_TR(B)QBT_TR[CONTEXT=misc]",
         "QBT_TR(KiB)QBT_TR[CONTEXT=misc]",
         "QBT_TR(MiB)QBT_TR[CONTEXT=misc]",
@@ -45,7 +45,7 @@ function friendlyUnit(value, isSpeed) {
     if ((value === undefined) || (value === null) || (value < 0))
         return "QBT_TR(Unknown)QBT_TR[CONTEXT=misc]";
 
-    var i = 0;
+    let i = 0;
     while (value >= 1024.0 && i < 6) {
         value /= 1024.0;
         ++i;
@@ -57,12 +57,12 @@ function friendlyUnit(value, isSpeed) {
         else return 3; // TiB, PiB, EiB
     }
 
-    var ret;
+    let ret;
     if (i === 0)
         ret = value + " " + units[i];
     else {
-        var precision = friendlyUnitPrecision(i);
-        var offset = Math.pow(10, precision);
+        const precision = friendlyUnitPrecision(i);
+        const offset = Math.pow(10, precision);
         // Don't round up
         ret = (Math.floor(offset * value) / offset).toFixed(precision) + " " + units[i];
     }
@@ -76,21 +76,21 @@ function friendlyUnit(value, isSpeed) {
  * JS counterpart of the function in src/misc.cpp
  */
 function friendlyDuration(seconds) {
-    var MAX_ETA = 8640000;
+    const MAX_ETA = 8640000;
     if (seconds < 0 || seconds >= MAX_ETA)
         return "∞";
     if (seconds === 0)
         return "0";
     if (seconds < 60)
         return "QBT_TR(< 1m)QBT_TR[CONTEXT=misc]";
-    var minutes = seconds / 60;
+    let minutes = seconds / 60;
     if (minutes < 60)
         return "QBT_TR(%1m)QBT_TR[CONTEXT=misc]".replace("%1", parseInt(minutes));
-    var hours = minutes / 60;
+    let hours = minutes / 60;
     minutes = minutes % 60;
     if (hours < 24)
         return "QBT_TR(%1h %2m)QBT_TR[CONTEXT=misc]".replace("%1", parseInt(hours)).replace("%2", parseInt(minutes));
-    var days = hours / 24;
+    const days = hours / 24;
     hours = hours % 24;
     if (days < 100)
         return "QBT_TR(%1d %2h)QBT_TR[CONTEXT=misc]".replace("%1", parseInt(days)).replace("%2", parseInt(hours));
@@ -98,7 +98,7 @@ function friendlyDuration(seconds) {
 }
 
 function friendlyPercentage(value) {
-    var percentage = (value * 100).round(1);
+    let percentage = (value * 100).round(1);
     if (isNaN(percentage) || (percentage < 0))
         percentage = 0;
     if (percentage > 100)
@@ -141,12 +141,12 @@ if (!Date.prototype.toISOString) {
  * JS counterpart of the function in src/misc.cpp
  */
 function parseHtmlLinks(text) {
-    var exp = /(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;
+    const exp = /(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;
     return text.replace(exp, "<a target='_blank' href='$1'>$1</a>");
 }
 
 function escapeHtml(str) {
-    var div = document.createElement('div');
+    const div = document.createElement('div');
     div.appendChild(document.createTextNode(str));
     return div.innerHTML;
 }
diff --git a/src/webui/www/private/scripts/mocha-init.js b/src/webui/www/private/scripts/mocha-init.js
index bde8beb9c..f4b48daa9 100644
--- a/src/webui/www/private/scripts/mocha-init.js
+++ b/src/webui/www/private/scripts/mocha-init.js
@@ -53,51 +53,60 @@ if (typeof localStorage == 'undefined') {
 }
 
 function getLocalStorageItem(name, defaultVal) {
-    var val = localStorage.getItem(name);
+    let val = localStorage.getItem(name);
     if (val === null || val === undefined)
         val = defaultVal;
     return val;
 }
 
-var saveWindowSize = function() {};
-var loadWindowWidth = function() {};
-var loadWindowHeight = function() {};
-var showDownloadPage = function() {};
-var globalUploadLimitFN = function() {};
-var uploadLimitFN = function() {};
-var shareRatioFN = function() {};
-var toggleSequentialDownloadFN = function() {};
-var toggleFirstLastPiecePrioFN = function() {};
-var setSuperSeedingFN = function() {};
-var setForceStartFN = function() {};
-var globalDownloadLimitFN = function() {};
-var StatisticsLinkFN = function() {};
-var downloadLimitFN = function() {};
-var deleteFN = function() {};
-var pauseFN = function() {};
-var startFN = function() {};
-var autoTorrentManagementFN = function() {};
-var recheckFN = function() {};
-var reannounceFN = function() {};
-var setLocationFN = function() {};
-var renameFN = function() {};
-var torrentNewCategoryFN = function() {};
-var torrentSetCategoryFN = function() {};
-var createCategoryFN = function() {};
-var editCategoryFN = function() {};
-var removeCategoryFN = function() {};
-var deleteUnusedCategoriesFN = function() {};
-var startTorrentsByCategoryFN = function() {};
-var pauseTorrentsByCategoryFN = function() {};
-var deleteTorrentsByCategoryFN = function() {};
-var copyNameFN = function() {};
-var copyMagnetLinkFN = function() {};
-var copyHashFN = function() {};
-var setQueuePositionFN = function() {};
+let saveWindowSize = function() {};
+let loadWindowWidth = function() {};
+let loadWindowHeight = function() {};
+let showDownloadPage = function() {};
+let globalUploadLimitFN = function() {};
+let uploadLimitFN = function() {};
+let shareRatioFN = function() {};
+let toggleSequentialDownloadFN = function() {};
+let toggleFirstLastPiecePrioFN = function() {};
+let setSuperSeedingFN = function() {};
+let setForceStartFN = function() {};
+let globalDownloadLimitFN = function() {};
+let StatisticsLinkFN = function() {};
+let downloadLimitFN = function() {};
+let deleteFN = function() {};
+let pauseFN = function() {};
+let startFN = function() {};
+let autoTorrentManagementFN = function() {};
+let recheckFN = function() {};
+let reannounceFN = function() {};
+let setLocationFN = function() {};
+let renameFN = function() {};
+let torrentNewCategoryFN = function() {};
+let torrentSetCategoryFN = function() {};
+let createCategoryFN = function() {};
+let editCategoryFN = function() {};
+let removeCategoryFN = function() {};
+let deleteUnusedCategoriesFN = function() {};
+let startTorrentsByCategoryFN = function() {};
+let pauseTorrentsByCategoryFN = function() {};
+let deleteTorrentsByCategoryFN = function() {};
+let torrentAddTagsFN = function() {};
+let torrentSetTagsFN = function() {};
+let torrentRemoveAllTagsFN = function() {};
+let createTagFN = function() {};
+let removeTagFN = function() {};
+let deleteUnusedTagsFN = function() {};
+let startTorrentsByTagFN = function() {};
+let pauseTorrentsByTagFN = function() {};
+let deleteTorrentsByTagFN = function() {};
+let copyNameFN = function() {};
+let copyMagnetLinkFN = function() {};
+let copyHashFN = function() {};
+let setQueuePositionFN = function() {};
 
-var initializeWindows = function() {
+const initializeWindows = function() {
     saveWindowSize = function(windowId) {
-        var size = $(windowId).getSize();
+        const size = $(windowId).getSize();
         localStorage.setItem('window_' + windowId + '_width', size.x);
         localStorage.setItem('window_' + windowId + '_height', size.y);
     };
@@ -124,8 +133,8 @@ var initializeWindows = function() {
     });
 
     showDownloadPage = function(urls) {
-        var id = 'downloadPage';
-        var contentUrl = 'download.html';
+        const id = 'downloadPage';
+        let contentUrl = 'download.html';
         if (urls && urls.length)
             contentUrl += '?urls=' + urls.join("|");
 
@@ -151,7 +160,7 @@ var initializeWindows = function() {
 
     addClickEvent('preferences', function(e) {
         new Event(e).stop();
-        var id = 'preferencesPage';
+        const id = 'preferencesPage';
         new MochaUI.Window({
             id: id,
             title: "QBT_TR(Options)QBT_TR[CONTEXT=OptionsDialog]",
@@ -176,7 +185,7 @@ var initializeWindows = function() {
 
     addClickEvent('upload', function(e) {
         new Event(e).stop();
-        var id = 'uploadPage';
+        const id = 'uploadPage';
         new MochaUI.Window({
             id: id,
             title: "QBT_TR(Upload local torrent)QBT_TR[CONTEXT=HttpServer]",
@@ -213,7 +222,7 @@ var initializeWindows = function() {
     };
 
     uploadLimitFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new MochaUI.Window({
                 id: 'uploadLimitPage',
@@ -232,16 +241,16 @@ var initializeWindows = function() {
     };
 
     shareRatioFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
-            var shareRatio = null;
-            var torrentsHaveSameShareRatio = true;
+            let shareRatio = null;
+            let torrentsHaveSameShareRatio = true;
 
             // check if all selected torrents have same share ratio
-            for (var i = 0; i < hashes.length; ++i) {
-                var hash = hashes[i];
-                var row = torrentsTable.rows[hash].full_data;
-                var origValues = row.ratio_limit + "|" + row.seeding_time_limit + "|" + row.max_ratio + "|" + row.max_seeding_time;
+            for (let i = 0; i < hashes.length; ++i) {
+                const hash = hashes[i];
+                const row = torrentsTable.rows[hash].full_data;
+                const origValues = row.ratio_limit + "|" + row.seeding_time_limit + "|" + row.max_ratio + "|" + row.max_seeding_time;
 
                 // initialize value
                 if (shareRatio === null)
@@ -254,7 +263,7 @@ var initializeWindows = function() {
             }
 
             // if all torrents have same share ratio, display that share ratio. else use the default
-            var orig = torrentsHaveSameShareRatio ? shareRatio : "";
+            const orig = torrentsHaveSameShareRatio ? shareRatio : "";
             new MochaUI.Window({
                 id: 'shareRatioPage',
                 title: "QBT_TR(Torrent Upload/Download Ratio Limiting)QBT_TR[CONTEXT=UpDownRatioDialog]",
@@ -271,7 +280,7 @@ var initializeWindows = function() {
     };
 
     toggleSequentialDownloadFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/toggleSequentialDownload',
@@ -285,7 +294,7 @@ var initializeWindows = function() {
     };
 
     toggleFirstLastPiecePrioFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/toggleFirstLastPiecePrio',
@@ -299,7 +308,7 @@ var initializeWindows = function() {
     };
 
     setSuperSeedingFN = function(val) {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/setSuperSeeding',
@@ -314,7 +323,7 @@ var initializeWindows = function() {
     };
 
     setForceStartFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/setForceStart',
@@ -345,7 +354,7 @@ var initializeWindows = function() {
     };
 
     StatisticsLinkFN = function() {
-        var id = 'statisticspage';
+        const id = 'statisticspage';
         new MochaUI.Window({
             id: id,
             title: 'QBT_TR(Statistics)QBT_TR[CONTEXT=StatsDialog]',
@@ -362,7 +371,7 @@ var initializeWindows = function() {
     };
 
     downloadLimitFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new MochaUI.Window({
                 id: 'downloadLimitPage',
@@ -381,7 +390,7 @@ var initializeWindows = function() {
     };
 
     deleteFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new MochaUI.Window({
                 id: 'confirmDeletionPage',
@@ -405,7 +414,7 @@ var initializeWindows = function() {
     });
 
     pauseFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/pause',
@@ -419,7 +428,7 @@ var initializeWindows = function() {
     };
 
     startFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/resume',
@@ -433,11 +442,11 @@ var initializeWindows = function() {
     };
 
     autoTorrentManagementFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
-            var enable = false;
+            let enable = false;
             hashes.each(function(hash, index) {
-                var row = torrentsTable.rows[hash];
+                const row = torrentsTable.rows[hash];
                 if (!row.full_data.auto_tmm)
                     enable = true;
             });
@@ -454,7 +463,7 @@ var initializeWindows = function() {
     };
 
     recheckFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/recheck',
@@ -468,7 +477,7 @@ var initializeWindows = function() {
     };
 
     reannounceFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/reannounce',
@@ -482,11 +491,11 @@ var initializeWindows = function() {
     };
 
     setLocationFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
-            var hash = hashes[0];
-            var row = torrentsTable.rows[hash];
-            var path = encodeURIComponent(row.full_data.save_path);
+            const hash = hashes[0];
+            const row = torrentsTable.rows[hash];
+            const path = encodeURIComponent(row.full_data.save_path);
             new MochaUI.Window({
                 id: 'setLocationPage',
                 title: "QBT_TR(Set location)QBT_TR[CONTEXT=TransferListWidget]",
@@ -504,10 +513,10 @@ var initializeWindows = function() {
     };
 
     renameFN = function() {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length == 1) {
-            var hash = hashes[0];
-            var row = torrentsTable.rows[hash];
+            const hash = hashes[0];
+            const row = torrentsTable.rows[hash];
             if (row) {
                 new MochaUI.Window({
                     id: 'renamePage',
@@ -527,8 +536,8 @@ var initializeWindows = function() {
     };
 
     torrentNewCategoryFN = function() {
-        var action = "set";
-        var hashes = torrentsTable.selectedRowsIds();
+        const action = "set";
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new MochaUI.Window({
                 id: 'newCategoryPage',
@@ -547,10 +556,10 @@ var initializeWindows = function() {
     };
 
     torrentSetCategoryFN = function(categoryHash) {
-        var categoryName = '';
+        let categoryName = '';
         if (categoryHash != 0)
             categoryName = category_list[categoryHash].name;
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/setCategory',
@@ -564,7 +573,7 @@ var initializeWindows = function() {
     };
 
     createCategoryFN = function() {
-        var action = "create";
+        const action = "create";
         new MochaUI.Window({
             id: 'newCategoryPage',
             title: "QBT_TR(New Category)QBT_TR[CONTEXT=CategoryFilterWidget]",
@@ -582,9 +591,9 @@ var initializeWindows = function() {
     };
 
     editCategoryFN = function(categoryHash) {
-        var action = "edit";
-        var categoryName = category_list[categoryHash].name;
-        var savePath = category_list[categoryHash].savePath;
+        const action = "edit";
+        const categoryName = category_list[categoryHash].name;
+        const savePath = category_list[categoryHash].savePath;
         new MochaUI.Window({
             id: 'editCategoryPage',
             title: "QBT_TR(Edit Category)QBT_TR[CONTEXT=TransferListWidget]",
@@ -602,7 +611,7 @@ var initializeWindows = function() {
     };
 
     removeCategoryFN = function(categoryHash) {
-        var categoryName = category_list[categoryHash].name;
+        const categoryName = category_list[categoryHash].name;
         new Request({
             url: 'api/v2/torrents/removeCategories',
             method: 'post',
@@ -614,9 +623,9 @@ var initializeWindows = function() {
     };
 
     deleteUnusedCategoriesFN = function() {
-        var categories = [];
-        for (var hash in category_list) {
-            if (torrentsTable.getFilteredTorrentsNumber('all', hash) === 0)
+        const categories = [];
+        for (const hash in category_list) {
+            if (torrentsTable.getFilteredTorrentsNumber('all', hash, TAGS_ALL) === 0)
                 categories.push(category_list[hash].name);
         }
         new Request({
@@ -630,7 +639,7 @@ var initializeWindows = function() {
     };
 
     startTorrentsByCategoryFN = function(categoryHash) {
-        var hashes = torrentsTable.getFilteredTorrentsHashes('all', categoryHash);
+        const hashes = torrentsTable.getFilteredTorrentsHashes('all', categoryHash, TAGS_ALL);
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/resume',
@@ -644,7 +653,7 @@ var initializeWindows = function() {
     };
 
     pauseTorrentsByCategoryFN = function(categoryHash) {
-        var hashes = torrentsTable.getFilteredTorrentsHashes('all', categoryHash);
+        const hashes = torrentsTable.getFilteredTorrentsHashes('all', categoryHash, TAGS_ALL);
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/pause',
@@ -658,7 +667,148 @@ var initializeWindows = function() {
     };
 
     deleteTorrentsByCategoryFN = function(categoryHash) {
-        var hashes = torrentsTable.getFilteredTorrentsHashes('all', categoryHash);
+        const hashes = torrentsTable.getFilteredTorrentsHashes('all', categoryHash, TAGS_ALL);
+        if (hashes.length) {
+            new MochaUI.Window({
+                id: 'confirmDeletionPage',
+                title: "QBT_TR(Deletion confirmation)QBT_TR[CONTEXT=confirmDeletionDlg]",
+                loadMethod: 'iframe',
+                contentURL: 'confirmdeletion.html?hashes=' + hashes.join("|"),
+                scrollbars: false,
+                resizable: false,
+                maximizable: false,
+                padding: 10,
+                width: 424,
+                height: 140
+            });
+            updateMainData();
+        }
+    };
+
+    torrentAddTagsFN = function() {
+        const action = "set";
+        const hashes = torrentsTable.selectedRowsIds();
+        if (hashes.length) {
+            new MochaUI.Window({
+                id: 'newTagPage',
+                title: "QBT_TR(Add Tags)QBT_TR[CONTEXT=TransferListWidget]",
+                loadMethod: 'iframe',
+                contentURL: 'newtag.html?action=' + action + '&hashes=' + hashes.join('|'),
+                scrollbars: false,
+                resizable: false,
+                maximizable: false,
+                paddingVertical: 0,
+                paddingHorizontal: 0,
+                width: 250,
+                height: 100
+            });
+        }
+    };
+
+    torrentSetTagsFN = function(tagHash, isSet) {
+        const tagName = ((tagHash === '0') ? '' : tagList[tagHash].name);
+        const hashes = torrentsTable.selectedRowsIds();
+        if (hashes.length) {
+            new Request({
+                url: (isSet ? 'api/v2/torrents/addTags' : 'api/v2/torrents/removeTags'),
+                method: 'post',
+                data: {
+                    hashes: hashes.join("|"),
+                    tags: tagName,
+                }
+            }).send();
+        }
+    };
+
+    torrentRemoveAllTagsFN = function() {
+        const hashes = torrentsTable.selectedRowsIds();
+        if (hashes.length) {
+            new Request({
+                url: ('api/v2/torrents/removeTags'),
+                method: 'post',
+                data: {
+                    hashes: hashes.join("|"),
+                }
+            }).send();
+        }
+    };
+
+    createTagFN = function() {
+        const action = "create";
+        new MochaUI.Window({
+            id: 'newTagPage',
+            title: "QBT_TR(New Tag)QBT_TR[CONTEXT=TagFilterWidget]",
+            loadMethod: 'iframe',
+            contentURL: 'newtag.html?action=' + action,
+            scrollbars: false,
+            resizable: false,
+            maximizable: false,
+            paddingVertical: 0,
+            paddingHorizontal: 0,
+            width: 250,
+            height: 100
+        });
+        updateMainData();
+    };
+
+    removeTagFN = function(tagHash) {
+        const tagName = tagList[tagHash].name;
+        new Request({
+            url: 'api/v2/torrents/deleteTags',
+            method: 'post',
+            data: {
+                tags: tagName
+            }
+        }).send();
+        setTagFilter(TAGS_ALL);
+    };
+
+    deleteUnusedTagsFN = function() {
+        const tags = [];
+        for (const hash in tagList) {
+            if (torrentsTable.getFilteredTorrentsNumber('all', CATEGORIES_ALL, hash) === 0)
+                tags.push(tagList[hash].name);
+        }
+        new Request({
+            url: 'api/v2/torrents/deleteTags',
+            method: 'post',
+            data: {
+                tags: tags.join(',')
+            }
+        }).send();
+        setTagFilter(TAGS_ALL);
+    };
+
+    startTorrentsByTagFN = function(tagHash) {
+        const hashes = torrentsTable.getFilteredTorrentsHashes('all', CATEGORIES_ALL, tagHash);
+        if (hashes.length) {
+            new Request({
+                url: 'api/v2/torrents/resume',
+                method: 'post',
+                data: {
+                    hashes: hashes.join("|")
+                }
+            }).send();
+            updateMainData();
+        }
+    };
+
+    pauseTorrentsByTagFN = function(tagHash) {
+        const hashes = torrentsTable.getFilteredTorrentsHashes('all', CATEGORIES_ALL, tagHash);
+        if (hashes.length) {
+            new Request({
+                url: 'api/v2/torrents/pause',
+                method: 'post',
+                data: {
+                    hashes: hashes.join("|")
+                }
+            }).send();
+            updateMainData();
+        }
+    };
+
+    deleteTorrentsByTagFN = function(tagHash) {
+        const hashes = torrentsTable.getFilteredTorrentsHashes('all', CATEGORIES_ALL, tagHash);
         if (hashes.length) {
             new MochaUI.Window({
                 id: 'confirmDeletionPage',
@@ -677,12 +827,12 @@ var initializeWindows = function() {
     };
 
     copyNameFN = function() {
-        var selectedRows = torrentsTable.selectedRowsIds();
-        var names = [];
+        const selectedRows = torrentsTable.selectedRowsIds();
+        const names = [];
         if (selectedRows.length) {
-            var rows = torrentsTable.getFilteredAndSortedRows();
-            for (var i = 0; i < selectedRows.length; ++i) {
-                var hash = selectedRows[i];
+            const rows = torrentsTable.getFilteredAndSortedRows();
+            for (let i = 0; i < selectedRows.length; ++i) {
+                const hash = selectedRows[i];
                 names.push(rows[hash].full_data.name);
             }
         }
@@ -690,12 +840,12 @@ var initializeWindows = function() {
     };
 
     copyMagnetLinkFN = function() {
-        var selectedRows = torrentsTable.selectedRowsIds();
-        var magnets = [];
+        const selectedRows = torrentsTable.selectedRowsIds();
+        const magnets = [];
         if (selectedRows.length) {
-            var rows = torrentsTable.getFilteredAndSortedRows();
-            for (var i = 0; i < selectedRows.length; ++i) {
-                var hash = selectedRows[i];
+            const rows = torrentsTable.getFilteredAndSortedRows();
+            for (let i = 0; i < selectedRows.length; ++i) {
+                const hash = selectedRows[i];
                 magnets.push(rows[hash].full_data.magnet_uri);
             }
         }
@@ -723,7 +873,7 @@ var initializeWindows = function() {
     ['pause', 'resume', 'recheck'].each(function(item) {
         addClickEvent(item, function(e) {
             new Event(e).stop();
-            var hashes = torrentsTable.selectedRowsIds();
+            const hashes = torrentsTable.selectedRowsIds();
             if (hashes.length) {
                 hashes.each(function(hash, index) {
                     new Request({
@@ -747,7 +897,7 @@ var initializeWindows = function() {
     });
 
     setQueuePositionFN = function(cmd) {
-        var hashes = torrentsTable.selectedRowsIds();
+        const hashes = torrentsTable.selectedRowsIds();
         if (hashes.length) {
             new Request({
                 url: 'api/v2/torrents/' + cmd,
@@ -762,7 +912,7 @@ var initializeWindows = function() {
 
     addClickEvent('about', function(e) {
         new Event(e).stop();
-        var id = 'aboutpage';
+        const id = 'aboutpage';
         new MochaUI.Window({
             id: id,
             title: 'QBT_TR(About qBittorrent)QBT_TR[CONTEXT=AboutDialog]',
diff --git a/src/webui/www/private/scripts/progressbar.js b/src/webui/www/private/scripts/progressbar.js
index c0ad50b2f..959c78be5 100644
--- a/src/webui/www/private/scripts/progressbar.js
+++ b/src/webui/www/private/scripts/progressbar.js
@@ -28,9 +28,9 @@
 
 'use strict';
 
-var ProgressBar = new Class({
+const ProgressBar = new Class({
     initialize: function(value, parameters) {
-        var vals = {
+        const vals = {
             'id': 'progressbar_' + (ProgressBars++),
             'value': $pick(value, 0),
             'width': 0,
@@ -42,7 +42,7 @@ var ProgressBar = new Class({
         };
         if (parameters && $type(parameters) == 'object') $extend(vals, parameters);
         if (vals.height < 12) vals.height = 12;
-        var obj = new Element('div', {
+        const obj = new Element('div', {
             'id': vals.id,
             'class': 'progressbar_wrapper',
             'styles': {
@@ -110,7 +110,7 @@ function ProgressBar_setValue(value) {
     this.vals.light.empty();
     this.vals.dark.appendText(value.round(1).toFixed(1) + '%');
     this.vals.light.appendText(value.round(1).toFixed(1) + '%');
-    var r = parseInt(this.vals.width * (value / 100));
+    const r = parseInt(this.vals.width * (value / 100));
     this.vals.dark.setStyle('clip', 'rect(0,' + r + 'px,' + this.vals.height + 'px,0)');
     this.vals.light.setStyle('clip', 'rect(0,' + this.vals.width + 'px,' + this.vals.height + 'px,' + r + 'px)');
 }
@@ -126,15 +126,15 @@ function ProgressBar_setWidth(value) {
 }
 
 function ProgressBar_checkForParent(id) {
-    var obj = $(id);
+    const obj = $(id);
     if (!obj) return;
     if (!obj.parentNode) return setTimeout('ProgressBar_checkForParent("' + id + '")', 1);
     obj.setStyle('width', '100%');
-    var w = obj.offsetWidth;
+    const w = obj.offsetWidth;
     obj.vals.dark.setStyle('width', w);
     obj.vals.light.setStyle('width', w);
     obj.vals.width = w;
     obj.setValue(obj.vals.value);
 }
 
-var ProgressBars = 0;
+let ProgressBars = 0;
diff --git a/src/webui/www/private/scripts/prop-files.js b/src/webui/www/private/scripts/prop-files.js
index 8ef02e61b..b3b648967 100644
--- a/src/webui/www/private/scripts/prop-files.js
+++ b/src/webui/www/private/scripts/prop-files.js
@@ -28,10 +28,10 @@
 
 'use strict';
 
-var is_seed = true;
-var current_hash = "";
+let is_seed = true;
+this.current_hash = "";
 
-var FilePriority = {
+const FilePriority = {
     "Ignored": 0,
     "Normal": 1,
     "High": 6,
@@ -39,7 +39,7 @@ var FilePriority = {
     "Mixed": -1
 };
 
-var normalizePriority = function(priority) {
+const normalizePriority = function(priority) {
     switch (priority) {
         case FilePriority.Ignored:
         case FilePriority.Normal:
@@ -52,30 +52,30 @@ var normalizePriority = function(priority) {
     }
 };
 
-var fileCheckboxChanged = function(e) {
-    var checkbox = e.target;
-    var priority = checkbox.checked ? FilePriority.Normal : FilePriority.Ignored;
-    var id = checkbox.get('data-id');
+const fileCheckboxChanged = function(e) {
+    const checkbox = e.target;
+    const priority = checkbox.checked ? FilePriority.Normal : FilePriority.Ignored;
+    const id = checkbox.get('data-id');
 
     setFilePriority(id, priority);
     setGlobalCheckboxState();
     return true;
 };
 
-var fileComboboxChanged = function(e) {
-    var combobox = e.target;
-    var newPriority = combobox.value;
-    var id = combobox.get('data-id');
+const fileComboboxChanged = function(e) {
+    const combobox = e.target;
+    const newPriority = combobox.value;
+    const id = combobox.get('data-id');
 
     setFilePriority(id, newPriority);
 };
 
-var isDownloadCheckboxExists = function(id) {
+const isDownloadCheckboxExists = function(id) {
     return ($('cbPrio' + id) !== null);
 };
 
-var createDownloadCheckbox = function(id, download) {
-    var checkbox = new Element('input');
+const createDownloadCheckbox = function(id, download) {
+    const checkbox = new Element('input');
     checkbox.set('type', 'checkbox');
     if (download)
         checkbox.set('checked', 'checked');
@@ -86,17 +86,17 @@ var createDownloadCheckbox = function(id, download) {
     return checkbox;
 };
 
-var updateDownloadCheckbox = function(id, download) {
-    var checkbox = $('cbPrio' + id);
+const updateDownloadCheckbox = function(id, download) {
+    const checkbox = $('cbPrio' + id);
     checkbox.checked = download;
 };
 
-var isPriorityComboExists = function(id) {
+const isPriorityComboExists = function(id) {
     return ($('comboPrio' + id) !== null);
 };
 
-var createPriorityOptionElement = function(priority, selected, html) {
-    var elem = new Element('option');
+const createPriorityOptionElement = function(priority, selected, html) {
+    const elem = new Element('option');
     elem.set('value', priority.toString());
     elem.set('html', html);
     if (selected)
@@ -104,8 +104,8 @@ var createPriorityOptionElement = function(priority, selected, html) {
     return elem;
 };
 
-var createPriorityCombo = function(id, selectedPriority) {
-    var select = new Element('select');
+const createPriorityCombo = function(id, selectedPriority) {
+    const select = new Element('select');
     select.set('id', 'comboPrio' + id);
     select.set('data-id', id);
     select.set('disabled', is_seed);
@@ -120,8 +120,8 @@ var createPriorityCombo = function(id, selectedPriority) {
     return select;
 };
 
-var updatePriorityCombo = function(id, selectedPriority) {
-    var combobox = $('comboPrio' + id);
+const updatePriorityCombo = function(id, selectedPriority) {
+    const combobox = $('comboPrio' + id);
 
     if (parseInt(combobox.value) !== selectedPriority)
         selectComboboxPriority(combobox, selectedPriority);
@@ -130,10 +130,10 @@ var updatePriorityCombo = function(id, selectedPriority) {
         combobox.disabled = is_seed;
 };
 
-var selectComboboxPriority = function(combobox, priority) {
-    var options = combobox.options;
-    for (var i = 0; i < options.length; ++i) {
-        var option = options[i];
+const selectComboboxPriority = function(combobox, priority) {
+    const options = combobox.options;
+    for (let i = 0; i < options.length; ++i) {
+        const option = options[i];
         if (parseInt(option.value) === priority)
             option.setAttribute('selected', '');
         else
@@ -143,9 +143,9 @@ var selectComboboxPriority = function(combobox, priority) {
     combobox.value = priority;
 };
 
-var switchCheckboxState = function() {
-    var rows = [];
-    var priority = FilePriority.Ignored;
+const switchCheckboxState = function() {
+    const rows = [];
+    let priority = FilePriority.Ignored;
 
     if ($('tristate_cb').state === "checked") {
         setGlobalCheckboxUnchecked();
@@ -169,7 +169,7 @@ var switchCheckboxState = function() {
         setFilePriority(rows, priority);
 };
 
-var setGlobalCheckboxState = function() {
+const setGlobalCheckboxState = function() {
     if (isAllCheckboxesChecked())
         setGlobalCheckboxChecked();
     else if (isAllCheckboxesUnchecked())
@@ -178,44 +178,44 @@ var setGlobalCheckboxState = function() {
         setGlobalCheckboxPartial();
 };
 
-var setGlobalCheckboxChecked = function() {
+const setGlobalCheckboxChecked = function() {
     $('tristate_cb').state = "checked";
     $('tristate_cb').indeterminate = false;
     $('tristate_cb').checked = true;
 };
 
-var setGlobalCheckboxUnchecked = function() {
+const setGlobalCheckboxUnchecked = function() {
     $('tristate_cb').state = "unchecked";
     $('tristate_cb').indeterminate = false;
     $('tristate_cb').checked = false;
 };
 
-var setGlobalCheckboxPartial = function() {
+const setGlobalCheckboxPartial = function() {
     $('tristate_cb').state = "partial";
     $('tristate_cb').indeterminate = true;
 };
 
-var isAllCheckboxesChecked = function() {
-    var checkboxes = $$('input.DownloadedCB');
-    for (var i = 0; i < checkboxes.length; ++i) {
+const isAllCheckboxesChecked = function() {
+    const checkboxes = $$('input.DownloadedCB');
+    for (let i = 0; i < checkboxes.length; ++i) {
         if (!checkboxes[i].checked)
             return false;
     }
     return true;
 };
 
-var isAllCheckboxesUnchecked = function() {
-    var checkboxes = $$('input.DownloadedCB');
-    for (var i = 0; i < checkboxes.length; ++i) {
+const isAllCheckboxesUnchecked = function() {
+    const checkboxes = $$('input.DownloadedCB');
+    for (let i = 0; i < checkboxes.length; ++i) {
         if (checkboxes[i].checked)
             return false;
     }
     return true;
 };
 
-var setFilePriority = function(id, priority) {
+const setFilePriority = function(id, priority) {
     if (current_hash === "") return;
-    var ids = Array.isArray(id) ? id : [id];
+    const ids = Array.isArray(id) ? id : [id];
 
     clearTimeout(loadTorrentFilesDataTimer);
     new Request({
@@ -232,20 +232,20 @@ var setFilePriority = function(id, priority) {
     }).send();
 
     ids.forEach(function(_id) {
-        var combobox = $('comboPrio' + _id);
+        const combobox = $('comboPrio' + _id);
         if (combobox !== null)
             selectComboboxPriority(combobox, priority);
     });
 };
 
-var loadTorrentFilesDataTimer;
-var loadTorrentFilesData = function() {
+let loadTorrentFilesDataTimer;
+const loadTorrentFilesData = function() {
     if ($('prop_files').hasClass('invisible')
         || $('propertiesPanel_collapseToggle').hasClass('panel-expand')) {
         // Tab changed, don't do anything
         return;
     }
-    var new_hash = torrentsTable.getCurrentTorrentHash();
+    const new_hash = torrentsTable.getCurrentTorrentHash();
     if (new_hash === "") {
         torrentFilesTable.clear();
         clearTimeout(loadTorrentFilesDataTimer);
@@ -256,7 +256,7 @@ var loadTorrentFilesData = function() {
         torrentFilesTable.clear();
         current_hash = new_hash;
     }
-    var url = new URI('api/v2/torrents/files?hash=' + current_hash);
+    const url = new URI('api/v2/torrents/files?hash=' + current_hash);
     new Request.JSON({
         url: url,
         noCache: true,
@@ -266,19 +266,19 @@ var loadTorrentFilesData = function() {
             loadTorrentFilesDataTimer = loadTorrentFilesData.delay(5000);
         },
         onSuccess: function(files) {
-            var selectedFiles = torrentFilesTable.selectedRowsIds();
+            const selectedFiles = torrentFilesTable.selectedRowsIds();
 
             if (!files) {
                 torrentFilesTable.clear();
                 return;
             }
 
-            var i = 0;
+            let i = 0;
             files.each(function(file) {
                 if (i === 0)
                     is_seed = file.is_seed;
 
-                var row = {
+                const row = {
                     rowId: i,
                     checked: (file.priority !== FilePriority.Ignored),
                     name: escapeHtml(file.name),
@@ -307,35 +307,35 @@ var loadTorrentFilesData = function() {
     }).send();
 };
 
-var updateTorrentFilesData = function() {
+updateTorrentFilesData = function() {
     clearTimeout(loadTorrentFilesDataTimer);
     loadTorrentFilesData();
 };
 
-var torrentFilesContextMenu = new ContextMenu({
+const torrentFilesContextMenu = new ContextMenu({
     targets: '#torrentFilesTableDiv tr',
     menu: 'torrentFilesMenu',
     actions: {
         FilePrioIgnore: function(element, ref) {
-            var selectedRows = torrentFilesTable.selectedRowsIds();
+            const selectedRows = torrentFilesTable.selectedRowsIds();
             if (selectedRows.length === 0) return;
 
             setFilePriority(selectedRows, FilePriority.Ignored);
         },
         FilePrioNormal: function(element, ref) {
-            var selectedRows = torrentFilesTable.selectedRowsIds();
+            const selectedRows = torrentFilesTable.selectedRowsIds();
             if (selectedRows.length === 0) return;
 
             setFilePriority(selectedRows, FilePriority.Normal);
         },
         FilePrioHigh: function(element, ref) {
-            var selectedRows = torrentFilesTable.selectedRowsIds();
+            const selectedRows = torrentFilesTable.selectedRowsIds();
             if (selectedRows.length === 0) return;
 
             setFilePriority(selectedRows, FilePriority.High);
         },
         FilePrioMaximum: function(element, ref) {
-            var selectedRows = torrentFilesTable.selectedRowsIds();
+            const selectedRows = torrentFilesTable.selectedRowsIds();
             if (selectedRows.length === 0) return;
 
             setFilePriority(selectedRows, FilePriority.Maximum);
@@ -346,8 +346,6 @@ var torrentFilesContextMenu = new ContextMenu({
         y: 2
     },
     onShow: function() {
-        var selectedRows = torrentFilesTable.selectedRowsIds();
-
         if (is_seed)
             this.hideItem('FilePrio');
         else
@@ -357,17 +355,17 @@ var torrentFilesContextMenu = new ContextMenu({
 
 torrentFilesTable.setup('torrentFilesTableDiv', 'torrentFilesTableFixedHeaderDiv', torrentFilesContextMenu);
 // inject checkbox into table header
-var tableHeaders = $$('#torrentFilesTableFixedHeaderDiv .dynamicTableHeader th');
+const tableHeaders = $$('#torrentFilesTableFixedHeaderDiv .dynamicTableHeader th');
 if (tableHeaders.length > 0) {
-    var checkbox = new Element('input');
+    const checkbox = new Element('input');
     checkbox.set('type', 'checkbox');
     checkbox.set('id', 'tristate_cb');
     checkbox.addEvent('click', switchCheckboxState);
 
-    var checkboxTH = tableHeaders[0];
+    const checkboxTH = tableHeaders[0];
     checkbox.injectInside(checkboxTH);
 }
 
 // default sort by name column
-if (torrentFilesTable.getSortedColunn() === null)
+if (torrentFilesTable.getSortedColumn() === null)
     torrentFilesTable.setSortedColumn('name');
diff --git a/src/webui/www/private/scripts/prop-general.js b/src/webui/www/private/scripts/prop-general.js
index 4f7b03fc7..2349c6b7a 100644
--- a/src/webui/www/private/scripts/prop-general.js
+++ b/src/webui/www/private/scripts/prop-general.js
@@ -28,7 +28,7 @@
 
 'use strict';
 
-var clearData = function() {
+const clearData = function() {
     $('time_elapsed').set('html', '');
     $('eta').set('html', '');
     $('nb_connections').set('html', '');
@@ -55,14 +55,14 @@ var clearData = function() {
     $('comment').set('html', '');
 };
 
-var loadTorrentDataTimer;
-var loadTorrentData = function() {
+let loadTorrentDataTimer;
+const loadTorrentData = function() {
     if ($('prop_general').hasClass('invisible')
         || $('propertiesPanel_collapseToggle').hasClass('panel-expand')) {
         // Tab changed, don't do anything
         return;
     }
-    var current_hash = torrentsTable.getCurrentTorrentHash();
+    const current_hash = torrentsTable.getCurrentTorrentHash();
     if (current_hash === "") {
         clearData();
         clearTimeout(loadTorrentDataTimer);
@@ -71,7 +71,7 @@ var loadTorrentData = function() {
     }
     // Display hash
     $('torrent_hash').set('html', current_hash);
-    var url = new URI('api/v2/torrents/properties?hash=' + current_hash);
+    const url = new URI('api/v2/torrents/properties?hash=' + current_hash);
     new Request.JSON({
         url: url,
         noCache: true,
@@ -84,7 +84,7 @@ var loadTorrentData = function() {
         onSuccess: function(data) {
             $('error_div').set('html', '');
             if (data) {
-                var temp;
+                let temp;
                 // Update Torrent data
                 if (data.seeding_time > 0)
                     temp = "QBT_TR(%1 (%2 this session))QBT_TR[CONTEXT=PropertiesWidget]"
@@ -193,7 +193,7 @@ var loadTorrentData = function() {
     }).send();
 };
 
-var updateTorrentData = function() {
+updateTorrentData = function() {
     clearTimeout(loadTorrentDataTimer);
     loadTorrentData();
 };
diff --git a/src/webui/www/private/scripts/prop-peers.js b/src/webui/www/private/scripts/prop-peers.js
index 99fce5c79..164077492 100644
--- a/src/webui/www/private/scripts/prop-peers.js
+++ b/src/webui/www/private/scripts/prop-peers.js
@@ -28,17 +28,17 @@
 
 'use strict';
 
-var loadTorrentPeersTimer;
-var syncTorrentPeersLastResponseId = 0;
-var show_flags = true;
-var loadTorrentPeersData = function() {
+let loadTorrentPeersTimer;
+let syncTorrentPeersLastResponseId = 0;
+let show_flags = true;
+const loadTorrentPeersData = function() {
     if ($('prop_peers').hasClass('invisible')
         || $('propertiesPanel_collapseToggle').hasClass('panel-expand')) {
         syncTorrentPeersLastResponseId = 0;
         torrentPeersTable.clear();
         return;
     }
-    var current_hash = torrentsTable.getCurrentTorrentHash();
+    const current_hash = torrentsTable.getCurrentTorrentHash();
     if (current_hash === "") {
         syncTorrentPeersLastResponseId = 0;
         torrentPeersTable.clear();
@@ -46,7 +46,7 @@ var loadTorrentPeersData = function() {
         loadTorrentPeersTimer = loadTorrentPeersData.delay(getSyncMainDataInterval());
         return;
     }
-    var url = new URI('api/v2/sync/torrentPeers');
+    const url = new URI('api/v2/sync/torrentPeers');
     url.setData('rid', syncTorrentPeersLastResponseId);
     url.setData('hash', current_hash);
     new Request.JSON({
@@ -60,13 +60,13 @@ var loadTorrentPeersData = function() {
         onSuccess: function(response) {
             $('error_div').set('html', '');
             if (response) {
-                var full_update = (response['full_update'] === true);
+                const full_update = (response['full_update'] === true);
                 if (full_update)
                     torrentPeersTable.clear();
                 if (response['rid'])
                     syncTorrentPeersLastResponseId = response['rid'];
                 if (response['peers']) {
-                    for (var key in response['peers']) {
+                    for (const key in response['peers']) {
                         response['peers'][key]['rowId'] = key;
 
                         if (response['peers'][key]['client'])
diff --git a/src/webui/www/private/scripts/prop-trackers.js b/src/webui/www/private/scripts/prop-trackers.js
index 2b530bb27..2aace0505 100644
--- a/src/webui/www/private/scripts/prop-trackers.js
+++ b/src/webui/www/private/scripts/prop-trackers.js
@@ -28,16 +28,16 @@
 
 'use strict';
 
-var current_hash = "";
+this.current_hash = "";
 
-var loadTrackersDataTimer;
-var loadTrackersData = function() {
+let loadTrackersDataTimer;
+const loadTrackersData = function() {
     if ($('prop_trackers').hasClass('invisible')
         || $('propertiesPanel_collapseToggle').hasClass('panel-expand')) {
         // Tab changed, don't do anything
         return;
     }
-    var new_hash = torrentsTable.getCurrentTorrentHash();
+    const new_hash = torrentsTable.getCurrentTorrentHash();
     if (new_hash === "") {
         torrentTrackersTable.clear();
         clearTimeout(loadTrackersDataTimer);
@@ -48,7 +48,7 @@ var loadTrackersData = function() {
         torrentTrackersTable.clear();
         current_hash = new_hash;
     }
-    var url = new URI('api/v2/torrents/trackers?hash=' + current_hash);
+    const url = new URI('api/v2/torrents/trackers?hash=' + current_hash);
     new Request.JSON({
         url: url,
         noCache: true,
@@ -58,13 +58,13 @@ var loadTrackersData = function() {
             loadTrackersDataTimer = loadTrackersData.delay(10000);
         },
         onSuccess: function(trackers) {
-            var selectedTrackers = torrentTrackersTable.selectedRowsIds();
+            const selectedTrackers = torrentTrackersTable.selectedRowsIds();
             torrentTrackersTable.clear();
 
             if (trackers) {
                 trackers.each(function(tracker) {
-                    var url = escapeHtml(tracker.url);
-                    var status;
+                    const url = escapeHtml(tracker.url);
+                    let status;
                     switch (tracker.status) {
                         case 0:
                             status = "QBT_TR(Disabled)QBT_TR[CONTEXT=TrackerListWidget]";
@@ -83,7 +83,7 @@ var loadTrackersData = function() {
                             break;
                     }
 
-                    var row = {
+                    const row = {
                         rowId: url,
                         tier: tracker.tier,
                         url: url,
@@ -108,12 +108,12 @@ var loadTrackersData = function() {
     }).send();
 };
 
-var updateTrackersData = function() {
+updateTrackersData = function() {
     clearTimeout(loadTrackersDataTimer);
     loadTrackersData();
 };
 
-var torrentTrackersContextMenu = new ContextMenu({
+const torrentTrackersContextMenu = new ContextMenu({
     targets: '#torrentTrackersTableDiv',
     menu: 'torrentTrackersMenu',
     actions: {
@@ -134,8 +134,8 @@ var torrentTrackersContextMenu = new ContextMenu({
         y: 2
     },
     onShow: function() {
-        var selectedTrackers = torrentTrackersTable.selectedRowsIds();
-        var containsStaticTracker = selectedTrackers.some(function(tracker) {
+        const selectedTrackers = torrentTrackersTable.selectedRowsIds();
+        const containsStaticTracker = selectedTrackers.some(function(tracker) {
             return (tracker.indexOf("** [") === 0);
         });
 
@@ -152,7 +152,7 @@ var torrentTrackersContextMenu = new ContextMenu({
     }
 });
 
-var addTrackerFN = function() {
+const addTrackerFN = function() {
     if (current_hash.length === 0) return;
     new MochaUI.Window({
         id: 'trackersPage',
@@ -173,10 +173,10 @@ var addTrackerFN = function() {
     });
 };
 
-var editTrackerFN = function(element) {
+const editTrackerFN = function(element) {
     if (current_hash.length === 0) return;
 
-    var trackerUrl = encodeURIComponent(element.childNodes[1].innerText);
+    const trackerUrl = encodeURIComponent(element.childNodes[1].innerText);
     new MochaUI.Window({
         id: 'trackersPage',
         title: "QBT_TR(Tracker editing)QBT_TR[CONTEXT=TrackerListWidget]",
@@ -196,10 +196,10 @@ var editTrackerFN = function(element) {
     });
 };
 
-var removeTrackerFN = function(element) {
+const removeTrackerFN = function(element) {
     if (current_hash.length === 0) return;
 
-    var selectedTrackers = torrentTrackersTable.selectedRowsIds();
+    const selectedTrackers = torrentTrackersTable.selectedRowsIds();
     new Request({
         url: 'api/v2/torrents/removeTrackers',
         method: 'post',
diff --git a/src/webui/www/private/scripts/prop-webseeds.js b/src/webui/www/private/scripts/prop-webseeds.js
index 4a6507a3d..bf270bfa0 100644
--- a/src/webui/www/private/scripts/prop-webseeds.js
+++ b/src/webui/www/private/scripts/prop-webseeds.js
@@ -28,7 +28,7 @@
 
 'use strict';
 
-var webseedsDynTable = new Class({
+const webseedsDynTable = new Class({
 
     initialize: function() {},
 
@@ -39,7 +39,7 @@ var webseedsDynTable = new Class({
 
     removeRow: function(url) {
         if (this.rows.has(url)) {
-            var tr = this.rows.get(url);
+            const tr = this.rows.get(url);
             tr.dispose();
             this.rows.erase(url);
             return true;
@@ -54,25 +54,25 @@ var webseedsDynTable = new Class({
     },
 
     updateRow: function(tr, row) {
-        var tds = tr.getElements('td');
-        for (var i = 0; i < row.length; ++i) {
+        const tds = tr.getElements('td');
+        for (let i = 0; i < row.length; ++i) {
             tds[i].set('html', row[i]);
         }
         return true;
     },
 
     insertRow: function(row) {
-        var url = row[0];
+        const url = row[0];
         if (this.rows.has(url)) {
-            var tableRow = this.rows.get(url);
+            const tableRow = this.rows.get(url);
             this.updateRow(tableRow, row);
             return;
         }
         //this.removeRow(id);
-        var tr = new Element('tr');
+        const tr = new Element('tr');
         this.rows.set(url, tr);
-        for (var i = 0; i < row.length; ++i) {
-            var td = new Element('td');
+        for (let i = 0; i < row.length; ++i) {
+            const td = new Element('td');
             td.set('html', row[i]);
             td.injectInside(tr);
         }
@@ -80,16 +80,16 @@ var webseedsDynTable = new Class({
     },
 });
 
-var current_hash = "";
+this.current_hash = "";
 
-var loadWebSeedsDataTimer;
-var loadWebSeedsData = function() {
+let loadWebSeedsDataTimer;
+const loadWebSeedsData = function() {
     if ($('prop_webseeds').hasClass('invisible')
         || $('propertiesPanel_collapseToggle').hasClass('panel-expand')) {
         // Tab changed, don't do anything
         return;
     }
-    var new_hash = torrentsTable.getCurrentTorrentHash();
+    const new_hash = torrentsTable.getCurrentTorrentHash();
     if (new_hash === "") {
         wsTable.removeAllRows();
         clearTimeout(loadWebSeedsDataTimer);
@@ -100,7 +100,7 @@ var loadWebSeedsData = function() {
         wsTable.removeAllRows();
         current_hash = new_hash;
     }
-    var url = new URI('api/v2/torrents/webseeds?hash=' + current_hash);
+    const url = new URI('api/v2/torrents/webseeds?hash=' + current_hash);
     new Request.JSON({
         url: url,
         noCache: true,
@@ -115,7 +115,7 @@ var loadWebSeedsData = function() {
             if (webseeds) {
                 // Update WebSeeds data
                 webseeds.each(function(webseed) {
-                    var row = [];
+                    const row = [];
                     row.length = 1;
                     row[0] = webseed.url;
                     wsTable.insertRow(row);
@@ -130,10 +130,10 @@ var loadWebSeedsData = function() {
     }).send();
 };
 
-var updateWebSeedsData = function() {
+updateWebSeedsData = function() {
     clearTimeout(loadWebSeedsDataTimer);
     loadWebSeedsData();
 };
 
-var wsTable = new webseedsDynTable();
+const wsTable = new webseedsDynTable();
 wsTable.setup($('webseedsTable'));
diff --git a/src/webui/www/private/scripts/speedslider.js b/src/webui/www/private/scripts/speedslider.js
index 634dcc370..32797a83d 100644
--- a/src/webui/www/private/scripts/speedslider.js
+++ b/src/webui/www/private/scripts/speedslider.js
@@ -31,17 +31,15 @@
 MochaUI.extend({
     addUpLimitSlider: function(hashes) {
         if ($('uplimitSliderarea')) {
-            var windowOptions = MochaUI.Windows.windowOptions;
-            var sliderFirst = true;
             // Get global upload limit
-            var maximum = 500;
-            var req = new Request({
+            let maximum = 500;
+            new Request({
                 url: 'api/v2/transfer/uploadLimit',
                 method: 'post',
                 data: {},
                 onSuccess: function(data) {
                     if (data) {
-                        var tmp = data.toInt();
+                        const tmp = data.toInt();
                         if (tmp > 0) {
                             maximum = tmp / 1024.0;
                         }
@@ -55,10 +53,10 @@ MochaUI.extend({
                     // Get torrents upload limit
                     // And create slider
                     if (hashes[0] == 'global') {
-                        var up_limit = maximum;
+                        let up_limit = maximum;
                         if (up_limit < 0) up_limit = 0;
                         maximum = 10000;
-                        var mochaSlide = new Slider($('uplimitSliderarea'), $('uplimitSliderknob'), {
+                        new Slider($('uplimitSliderarea'), $('uplimitSliderknob'), {
                             steps: maximum,
                             offset: 0,
                             initialStep: up_limit.round(),
@@ -84,7 +82,7 @@ MochaUI.extend({
                         }
                     }
                     else {
-                        var req = new Request.JSON({
+                        new Request.JSON({
                             url: 'api/v2/torrents/uploadLimit',
                             noCache : true,
                             method: 'post',
@@ -93,14 +91,14 @@ MochaUI.extend({
                             },
                             onSuccess: function(data) {
                                 if (data) {
-                                    var up_limit = data[hashes[0]];
-                                    for(var key in data)
+                                    let up_limit = data[hashes[0]];
+                                    for(const key in data)
                                         if (up_limit != data[key]) {
                                             up_limit = 0;
                                             break;
                                         }
                                     if (up_limit < 0) up_limit = 0;
-                                    var mochaSlide = new Slider($('uplimitSliderarea'), $('uplimitSliderknob'), {
+                                    new Slider($('uplimitSliderarea'), $('uplimitSliderknob'), {
                                         steps: maximum,
                                         offset: 0,
                                         initialStep: (up_limit / 1024.0).round(),
@@ -135,17 +133,15 @@ MochaUI.extend({
 
     addDlLimitSlider: function(hashes) {
         if ($('dllimitSliderarea')) {
-            var windowOptions = MochaUI.Windows.windowOptions;
-            var sliderFirst = true;
             // Get global upload limit
-            var maximum = 500;
-            var req = new Request({
+            let maximum = 500;
+            new Request({
                 url: 'api/v2/transfer/downloadLimit',
                 method: 'post',
                 data: {},
                 onSuccess: function(data) {
                     if (data) {
-                        var tmp = data.toInt();
+                        const tmp = data.toInt();
                         if (tmp > 0) {
                             maximum = tmp / 1024.0;
                         }
@@ -159,10 +155,10 @@ MochaUI.extend({
                     // Get torrents download limit
                     // And create slider
                     if (hashes[0] == 'global') {
-                        var dl_limit = maximum;
+                        let dl_limit = maximum;
                         if (dl_limit < 0) dl_limit = 0;
                         maximum = 10000;
-                        var mochaSlide = new Slider($('dllimitSliderarea'), $('dllimitSliderknob'), {
+                        new Slider($('dllimitSliderarea'), $('dllimitSliderknob'), {
                             steps: maximum,
                             offset: 0,
                             initialStep: dl_limit.round(),
@@ -188,7 +184,7 @@ MochaUI.extend({
                         }
                     }
                     else {
-                        var req = new Request.JSON({
+                        new Request.JSON({
                             url: 'api/v2/torrents/downloadLimit',
                             noCache : true,
                             method: 'post',
@@ -197,14 +193,14 @@ MochaUI.extend({
                             },
                             onSuccess: function(data) {
                                 if (data) {
-                                    var dl_limit = data[hashes[0]];
-                                    for(var key in data)
+                                    let dl_limit = data[hashes[0]];
+                                    for(const key in data)
                                         if (dl_limit != data[key]) {
                                             dl_limit = 0;
                                             break;
                                         }
                                     if (dl_limit < 0) dl_limit = 0;
-                                    var mochaSlide = new Slider($('dllimitSliderarea'), $('dllimitSliderknob'), {
+                                    new Slider($('dllimitSliderarea'), $('dllimitSliderknob'), {
                                         steps: maximum,
                                         offset: 0,
                                         initialStep: (dl_limit / 1024.0).round(),
diff --git a/src/webui/www/private/search.html b/src/webui/www/private/search.html
index e158d9962..2ff92d075 100644
--- a/src/webui/www/private/search.html
+++ b/src/webui/www/private/search.html
@@ -153,42 +153,42 @@
 <script>
     'use strict';
 
-    var loadSearchResultsTimer;
-    var loadSearchPluginsTimer;
-    var searchResultsRowId = 0;
-    var searchRunning = false;
-    var requestCount = 0;
-    var searchPlugins = [];
-    var prevSearchPluginsResponse;
-    var searchPattern = "";
-    var searchFilterPattern = "";
-    var searchSeedsFilter = {
+    let loadSearchResultsTimer;
+    let loadSearchPluginsTimer;
+    let searchResultsRowId = 0;
+    let searchRunning = false;
+    let requestCount = 0;
+    let searchPlugins = [];
+    let prevSearchPluginsResponse;
+    let searchPattern = "";
+    let searchFilterPattern = "";
+    const searchSeedsFilter = {
         min: 0,
         max: 0
     };
-    var searchSizeFilter = {
+    const searchSizeFilter = {
         min: 0.00,
         minUnit: 2, // B = 0, KiB = 1, MiB = 2, GiB = 3, TiB = 4, PiB = 5, EiB = 6
         max: 0.00,
         maxUnit: 3
     };
-    var prevNameFilterValue;
-    var selectedCategory = "QBT_TR(All categories)QBT_TR[CONTEXT=SearchEngineWidget]";
-    var selectedPlugin = "all";
-    var prevSelectedPlugin;
-    var activeSearchId = null;
+    let prevNameFilterValue;
+    let selectedCategory = "QBT_TR(All categories)QBT_TR[CONTEXT=SearchEngineWidget]";
+    let selectedPlugin = "all";
+    let prevSelectedPlugin;
+    let activeSearchId = null;
 
-    var initSearchTab = function() {
+    const initSearchTab = function() {
         // load "Search in" preference from local storage
         $('searchInTorrentName').set('value', (localStorage.getItem('search_in_filter') === "names") ? "names" : "everywhere");
 
         searchResultsTable.setup('searchResultsTableDiv', 'searchResultsTableFixedHeaderDiv', null);
         getPlugins();
 
-        var searchInNameFilterTimer = null;
+        let searchInNameFilterTimer = null;
         // listen for changes to searchInNameFilter
         $('searchInNameFilter').addEvent('input', function() {
-            var value = $('searchInNameFilter').get("value");
+            const value = $('searchInNameFilter').get("value");
             if (value !== prevNameFilterValue) {
                 prevNameFilterValue = value;
                 clearTimeout(searchInNameFilterTimer);
@@ -206,7 +206,7 @@
                     // accept enter key as a click
                     new Event(e).stop();
 
-                    var elem = e.event.srcElement;
+                    const elem = e.event.srcElement;
                     if (elem.className.contains("searchInputField")) {
                         $('startSearchButton').click();
                         return;
@@ -231,7 +231,7 @@
         }).activate();
     };
 
-    var startSearch = function(pattern, category, plugins) {
+    const startSearch = function(pattern, category, plugins) {
         clearTimeout(loadSearchResultsTimer);
         searchResultsTable.clear();
         $('numSearchResultsVisible').set('html', searchResultsTable.getFilteredAndSortedRows().length);
@@ -239,7 +239,7 @@
         searchResultsRowId = 0;
         requestCount = 0;
 
-        var url = new URI('api/v2/search/start');
+        const url = new URI('api/v2/search/start');
         new Request.JSON({
             url: url,
             noCache: true,
@@ -258,8 +258,8 @@
         }).send();
     };
 
-    var stopSearch = function() {
-        var url = new URI('api/v2/search/stop');
+    const stopSearch = function() {
+        const url = new URI('api/v2/search/stop');
         new Request({
             url: url,
             noCache: true,
@@ -273,11 +273,11 @@
         }).send();
     };
 
-    var startStopSearch = function() {
+    const startStopSearch = function() {
         if (!searchRunning || !activeSearchId) {
-            var pattern = $('searchPattern').getProperty('value').trim();
-            var category = $('categorySelect').getProperty('value');
-            var plugins = $('pluginsSelect').getProperty('value');
+            const pattern = $('searchPattern').getProperty('value').trim();
+            let category = $('categorySelect').getProperty('value');
+            const plugins = $('pluginsSelect').getProperty('value');
 
             if (!pattern || !category || !plugins) return;
             if (category === "QBT_TR(All categories)QBT_TR[CONTEXT=SearchEngineWidget]")
@@ -293,22 +293,22 @@
         }
     };
 
-    var openSearchTorrentDescription = function() {
+    const openSearchTorrentDescription = function() {
         searchResultsTable.selectedRowsIds().each(function(rowId) {
             window.open(searchResultsTable.rows.get(rowId).full_data.descrLink, "_blank");
         });
     };
 
-    var copySearchTorrentUrl = function() {
-        var urls = [];
+    const copySearchTorrentUrl = function() {
+        const urls = [];
         searchResultsTable.selectedRowsIds().each(function(rowId) {
             urls.push(searchResultsTable.rows.get(rowId).full_data.descrLink);
         });
         return urls.join("\n");
     };
 
-    var downloadSearchTorrent = function() {
-        var urls = [];
+    const downloadSearchTorrent = function() {
+        const urls = [];
         searchResultsTable.selectedRowsIds().each(function(rowId) {
             urls.push(encodeURIComponent(searchResultsTable.rows.get(rowId).full_data.fileUrl));
         });
@@ -319,8 +319,8 @@
         showDownloadPage(urls);
     };
 
-    var manageSearchPlugins = function() {
-        var id = 'searchPlugins';
+    const manageSearchPlugins = function() {
+        const id = 'searchPlugins';
         if (!$(id))
             new MochaUI.Window({
                 id: id,
@@ -345,16 +345,16 @@
             });
     };
 
-    var loadSearchPlugins = function() {
+    const loadSearchPlugins = function() {
         getPlugins();
         loadSearchPluginsTimer = loadSearchPlugins.delay(2000);
     };
 
-    var categorySelected = function() {
+    const categorySelected = function() {
         selectedCategory = $("categorySelect").get("value");
     };
 
-    var pluginSelected = function() {
+    const pluginSelected = function() {
         selectedPlugin = $("pluginsSelect").get("value");
 
         if (selectedPlugin !== prevSelectedPlugin) {
@@ -363,23 +363,23 @@
         }
     };
 
-    var reselectCategory = function() {
-        for (var i = 0; i < $("categorySelect").options.length; ++i)
+    const reselectCategory = function() {
+        for (let i = 0; i < $("categorySelect").options.length; ++i)
             if ($("categorySelect").options[i].get("value") === selectedCategory)
                 $("categorySelect").options[i].selected = true;
 
         categorySelected();
     };
 
-    var reselectPlugin = function() {
-        for (var i = 0; i < $("pluginsSelect").options.length; ++i)
+    const reselectPlugin = function() {
+        for (let i = 0; i < $("pluginsSelect").options.length; ++i)
             if ($("pluginsSelect").options[i].get("value") === selectedPlugin)
                 $("pluginsSelect").options[i].selected = true;
 
         pluginSelected();
     };
 
-    var resetSearchState = function() {
+    const resetSearchState = function() {
         clearTimeout(loadSearchResultsTimer);
         $('startSearchButton').set('text', 'QBT_TR(Search)QBT_TR[CONTEXT=SearchEngineWidget]');
         searchResultsRowId = 0;
@@ -387,9 +387,9 @@
         activeSearchId = null;
     };
 
-    var getSearchCategories = function() {
-        var populateCategorySelect = function(categories) {
-            var categoryHtml = [];
+    const getSearchCategories = function() {
+        const populateCategorySelect = function(categories) {
+            const categoryHtml = [];
             categories.each(function(category) {
                 categoryHtml.push("<option>" + category + "</option>");
             });
@@ -402,9 +402,9 @@
             $('categorySelect').set('html', categoryHtml.join(""));
         };
 
-        var selectedPlugin = $('pluginsSelect').get("value");
+        const selectedPlugin = $('pluginsSelect').get("value");
         if ((selectedPlugin === "all") || (selectedPlugin === "enabled")) {
-            var url = new URI('api/v2/search/categories');
+            const url = new URI('api/v2/search/categories');
             url.setData('name', selectedPlugin);
             new Request.JSON({
                 url: url,
@@ -416,8 +416,8 @@
             }).send();
         }
         else {
-            var plugins = ["QBT_TR(All categories)QBT_TR[CONTEXT=SearchEngineWidget]"];
-            var plugin = getPlugin(selectedPlugin);
+            let plugins = ["QBT_TR(All categories)QBT_TR[CONTEXT=SearchEngineWidget]"];
+            const plugin = getPlugin(selectedPlugin);
             if (plugin !== null)
                 plugins = plugins.concat(plugin.supportedCategories);
 
@@ -427,7 +427,7 @@
         reselectCategory();
     };
 
-    var getPlugins = function() {
+    const getPlugins = function() {
         new Request.JSON({
             url: new URI('api/v2/search/plugins'),
             noCache: true,
@@ -437,11 +437,11 @@
                     prevSearchPluginsResponse = response;
                     searchPlugins = response;
 
-                    var pluginsHtml = [];
+                    const pluginsHtml = [];
                     pluginsHtml.push('<option value="enabled">QBT_TR(Only enabled)QBT_TR[CONTEXT=SearchEngineWidget]</option>');
                     pluginsHtml.push('<option value="all">QBT_TR(All plugins)QBT_TR[CONTEXT=SearchEngineWidget]</option>');
 
-                    var searchPluginsEmpty = (searchPlugins.length === 0);
+                    const searchPluginsEmpty = (searchPlugins.length === 0);
                     if (searchPluginsEmpty) {
                         $('searchResultsNoPlugins').style.display = "block";
                         $('searchResultsFilters').style.display = "none";
@@ -453,9 +453,9 @@
                         $('searchResultsTableContainer').style.display = "block";
 
                         // sort plugins alphabetically
-                        var allPlugins = searchPlugins.sort(function(pluginA, pluginB) {
-                            var a = pluginA.fullName.toLowerCase();
-                            var b = pluginB.fullName.toLowerCase();
+                        const allPlugins = searchPlugins.sort(function(pluginA, pluginB) {
+                            const a = pluginA.fullName.toLowerCase();
+                            const b = pluginB.fullName.toLowerCase();
                             if (a < b) return -1;
                             if (a > b) return 1;
                             return 0;
@@ -489,15 +489,15 @@
         }).send();
     };
 
-    var getPlugin = function(name) {
-        for (var i = 0; i < searchPlugins.length; ++i)
+    const getPlugin = function(name) {
+        for (let i = 0; i < searchPlugins.length; ++i)
             if (searchPlugins[i].name === name)
                 return searchPlugins[i];
 
         return null;
     };
 
-    var searchInTorrentName = function() {
+    const searchInTorrentName = function() {
         if ($('searchInTorrentName').get('value') === "names")
             localStorage.setItem('search_in_filter', "names");
         else
@@ -506,7 +506,7 @@
         searchFilterChanged();
     };
 
-    var resetFilters = function() {
+    const resetFilters = function() {
         // reset filters
         $('searchMinSeedsFilter').set('value', '0');
         $('searchMaxSeedsFilter').set('value', '0');
@@ -516,14 +516,14 @@
         $('searchMaxSizePrefix').set('value', '3'); // GiB
     };
 
-    var searchSeedsFilterChanged = function() {
+    const searchSeedsFilterChanged = function() {
         searchSeedsFilter.min = $('searchMinSeedsFilter').get('value');
         searchSeedsFilter.max = $('searchMaxSeedsFilter').get('value');
 
         searchFilterChanged();
     };
 
-    var searchSizeFilterChanged = function() {
+    const searchSizeFilterChanged = function() {
         searchSizeFilter.min = $('searchMinSizeFilter').get('value');
         searchSizeFilter.minUnit = $('searchMinSizePrefix').get('value');
         searchSizeFilter.max = $('searchMaxSizeFilter').get('value');
@@ -532,17 +532,17 @@
         searchFilterChanged();
     };
 
-    var searchSizeFilterPrefixChanged = function() {
+    const searchSizeFilterPrefixChanged = function() {
         if (($('searchMinSizeFilter').get('value') != 0) || ($('searchMaxSizeFilter').get('value') != 0))
             searchSizeFilterChanged();
     };
 
-    var searchFilterChanged = function() {
+    const searchFilterChanged = function() {
         searchResultsTable.updateTable();
         $('numSearchResultsVisible').set('html', searchResultsTable.getFilteredAndSortedRows().length);
     };
 
-    var setupSearchTableEvents = function(enable) {
+    const setupSearchTableEvents = function(enable) {
         if (enable)
             $$(".searchTableRow").each(function(target) {
                 target.addEventListener('dblclick', downloadSearchTorrent, false);
@@ -553,9 +553,9 @@
             });
     };
 
-    var loadSearchResultsData = function() {
-        var maxResults = 500;
-        var url = new URI('api/v2/search/results');
+    const loadSearchResultsData = function() {
+        const maxResults = 500;
+        const url = new URI('api/v2/search/results');
         new Request.JSON({
             url: url,
             noCache: true,
@@ -589,10 +589,10 @@
                     setupSearchTableEvents(false);
 
                     if (response.results) {
-                        var results = response.results;
-                        for (var i = 0; i < results.length; ++i) {
-                            var result = results[i];
-                            var row = {
+                        const results = response.results;
+                        for (let i = 0; i < results.length; ++i) {
+                            const result = results[i];
+                            const row = {
                                 rowId: searchResultsRowId,
                                 descrLink: result.descrLink,
                                 fileName: result.fileName,
@@ -622,7 +622,7 @@
                     setupSearchTableEvents(true);
                 }
 
-                var timeout = 1000;
+                let timeout = 1000;
                 if (requestCount > 30)
                     timeout = 3000;
                 else if (requestCount > 10)
@@ -635,7 +635,7 @@
         }).send();
     };
 
-    var updateSearchResultsData = function() {
+    const updateSearchResultsData = function() {
         clearTimeout(loadSearchResultsTimer);
         loadSearchResultsTimer = loadSearchResultsData.delay(500);
     };
diff --git a/src/webui/www/private/searchplugins.html b/src/webui/www/private/searchplugins.html
index b4a427723..a757ff652 100644
--- a/src/webui/www/private/searchplugins.html
+++ b/src/webui/www/private/searchplugins.html
@@ -79,11 +79,11 @@
 <script>
     'use strict';
 
-    var searchPluginsTableContextMenu;
-    var prevOffsetLeft;
-    var prevOffsetTop;
+    this.searchPluginsTableContextMenu = undefined;
+    this.prevOffsetLeft = undefined;
+    this.prevOffsetTop = undefined;
 
-    var initSearchPlugins = function() {
+    this.initSearchPlugins = function() {
         searchPluginsTableContextMenu = new SearchPluginsTableContextMenu({
             targets: '.searchPluginsTableRow',
             menu: 'searchPluginsTableMenu',
@@ -97,11 +97,11 @@
         updateSearchPluginsTable();
     };
 
-    var closeSearchWindow = function(id) {
+    this.closeSearchWindow = function(id) {
         window.parent.MochaUI.closeWindow(window.parent.$(id));
     };
 
-    var installPlugin = function(path) {
+    this.installPlugin = function(path) {
         new MochaUI.Window({
             id: 'installSearchPlugin',
             title: "QBT_TR(Install plugin)QBT_TR[CONTEXT=PluginSourceDlg]",
@@ -117,9 +117,9 @@
         });
     };
 
-    var uninstallPlugin = function() {
-        var plugins = searchPluginsTable.selectedRowsIds().join('|');
-        var url = new URI('api/v2/search/uninstallPlugin');
+    this.uninstallPlugin = function() {
+        const plugins = searchPluginsTable.selectedRowsIds().join('|');
+        const url = new URI('api/v2/search/uninstallPlugin');
         new Request({
             url: url,
             noCache: true,
@@ -130,13 +130,13 @@
         }).send();
     };
 
-    var enablePlugin = function() {
-        var plugins = searchPluginsTable.selectedRowsIds();
-        var enable = true;
+    this.enablePlugin = function() {
+        const plugins = searchPluginsTable.selectedRowsIds();
+        let enable = true;
         if (plugins && plugins.length)
             enable = !getPlugin(plugins[0]).enabled;
 
-        var url = new URI('api/v2/search/enablePlugin');
+        const url = new URI('api/v2/search/enablePlugin');
         new Request({
             url: url,
             noCache: true,
@@ -148,8 +148,8 @@
         }).send();
     };
 
-    var checkForUpdates = function() {
-        var url = new URI('api/v2/search/updatePlugins');
+    this.checkForUpdates = function() {
+        const url = new URI('api/v2/search/updatePlugins');
         new Request({
             url: url,
             noCache: true,
@@ -157,7 +157,7 @@
         }).send();
     };
 
-    var calculateContextMenuOffsets = function() {
+    this.calculateContextMenuOffsets = function() {
         prevOffsetLeft = document.getElementById("searchPlugins").getBoundingClientRect().left;
         prevOffsetTop = document.getElementById("searchPlugins").getBoundingClientRect().top;
 
@@ -167,13 +167,13 @@
         };
     };
 
-    var updateSearchPluginsTableContextMenuOffset = function() {
+    this.updateSearchPluginsTableContextMenuOffset = function() {
         // only re-calculate if window has moved
         if ((prevOffsetLeft !== document.getElementById("searchPlugins").getBoundingClientRect().left) || (prevOffsetTop !== document.getElementById("searchPlugins").getBoundingClientRect().top))
             searchPluginsTableContextMenu.options.offsets = calculateContextMenuOffsets();
     };
 
-    var setupSearchPluginTableEvents = function(enable) {
+    this.setupSearchPluginTableEvents = function(enable) {
         if (enable)
             $$(".searchPluginsTableRow").each(function(target) {
                 target.addEventListener('dblclick', enablePlugin, false);
@@ -186,15 +186,15 @@
             });
     };
 
-    var updateSearchPluginsTable = function() {
+    this.updateSearchPluginsTable = function() {
         // clear event listeners
         setupSearchPluginTableEvents(false);
 
-        var oldPlugins = Object.keys(searchPluginsTable.rows);
+        const oldPlugins = Object.keys(searchPluginsTable.rows);
         // remove old rows from the table
-        for (var i = 0; i < oldPlugins.length; ++i) {
-            var found = false;
-            for (var j = 0; j < searchPlugins.length; ++j) {
+        for (let i = 0; i < oldPlugins.length; ++i) {
+            let found = false;
+            for (let j = 0; j < searchPlugins.length; ++j) {
                 if (searchPlugins[j].name === oldPlugins[i]) {
                     found = true;
                     break;
@@ -204,7 +204,7 @@
                 searchPluginsTable.removeRow(oldPlugins[i]);
         }
 
-        for (var i = 0; i < searchPlugins.length; ++i) {
+        for (let i = 0; i < searchPlugins.length; ++i) {
             searchPlugins[i].rowId = searchPlugins[i].name;
             searchPluginsTable.updateRowData(searchPlugins[i]);
         }
diff --git a/src/webui/www/private/setlocation.html b/src/webui/www/private/setlocation.html
index e9e4498ac..28f7ddf7e 100644
--- a/src/webui/www/private/setlocation.html
+++ b/src/webui/www/private/setlocation.html
@@ -30,7 +30,7 @@
         }).activate();
 
         window.addEvent('domready', function() {
-            var path = new URI().getData('path');
+            const path = new URI().getData('path');
             // set text field to current value
             if (path)
                 $('setLocation').value = escapeHtml(decodeURIComponent(path));
@@ -39,13 +39,13 @@
             $('setLocationButton').addEvent('click', function(e) {
                 new Event(e).stop();
                 // check field
-                var location = $('setLocation').value.trim();
+                const location = $('setLocation').value.trim();
                 if (location === null || location === "") {
                     $('error_div').set('text', 'QBT_TR(Save path is empty)QBT_TR[CONTEXT=TorrentsController]');
                     return false;
                 }
 
-                var hashesList = new URI().getData('hashes');
+                const hashesList = new URI().getData('hashes');
                 new Request({
                     url: 'api/v2/torrents/setLocation',
                     method: 'post',
diff --git a/src/webui/www/private/shareratio.html b/src/webui/www/private/shareratio.html
index ea42edc45..f93a36117 100644
--- a/src/webui/www/private/shareratio.html
+++ b/src/webui/www/private/shareratio.html
@@ -11,8 +11,8 @@
     <script>
         'use strict';
 
-        var UseGlobalLimit = -2;
-        var NoLimit = -1;
+        const UseGlobalLimit = -2;
+        const NoLimit = -1;
 
         new Keyboard({
             defaultEventType: 'keydown',
@@ -33,10 +33,10 @@
         }).activate();
 
         window.addEvent('domready', function() {
-            var hashesList = new URI().getData('hashes').split('|');
-            var origValues = new URI().getData('orig').split('|');
+            const hashesList = new URI().getData('hashes').split('|');
+            const origValues = new URI().getData('orig').split('|');
 
-            var values = {
+            const values = {
                 ratioLimit: friendlyFloat(origValues[0], 2),
                 seedingTimeLimit: parseInt(origValues[1]),
                 maxRatio: friendlyFloat(origValues[2], 2),
@@ -74,9 +74,9 @@
                     return false;
                 }
 
-                var shareLimit = getSelectedRadioValue('shareLimit');
-                var ratioLimitValue = 0.00;
-                var seedingTimeLimitValue = 0;
+                const shareLimit = getSelectedRadioValue('shareLimit');
+                let ratioLimitValue = 0.00;
+                let seedingTimeLimitValue = 0;
 
                 if (shareLimit === 'default') {
                     ratioLimitValue = seedingTimeLimitValue = UseGlobalLimit;
@@ -108,10 +108,10 @@
         });
 
         function getSelectedRadioValue(name) {
-            var radios = document.getElementsByName(name);
+            const radios = document.getElementsByName(name);
 
-            for (var i = 0; i < radios.length; ++i) {
-                var radio = radios[i];
+            for (let i = 0; i < radios.length; ++i) {
+                const radio = radios[i];
                 if (radio.checked) {
                     return (radio).get('value');
                 }
@@ -119,17 +119,17 @@
         }
 
         function setSelectedRadioValue(name, value) {
-            var radios = document.getElementsByName(name);
+            const radios = document.getElementsByName(name);
 
-            for (var i = 0; i < radios.length; ++i) {
-                var radio = radios[i];
+            for (let i = 0; i < radios.length; ++i) {
+                const radio = radios[i];
                 if (radio.value === value)
                     radio.checked = true;
             }
         }
 
         function shareLimitChanged() {
-            var customShareLimit = getSelectedRadioValue('shareLimit') === 'custom';
+            const customShareLimit = getSelectedRadioValue('shareLimit') === 'custom';
             $('setRatio').set('disabled', !customShareLimit);
             $('setMinutes').set('disabled', !customShareLimit);
 
diff --git a/src/webui/www/private/transferlist.html b/src/webui/www/private/transferlist.html
index 1816ed97a..2eed41656 100644
--- a/src/webui/www/private/transferlist.html
+++ b/src/webui/www/private/transferlist.html
@@ -19,7 +19,7 @@
     'use strict';
 
     //create a context menu
-    var torrentsTableContextMenu = new TorrentsTableContextMenu({
+    const torrentsTableContextMenu = new TorrentsTableContextMenu({
         targets: '.torrentsTableContextMenuTarget',
         menu: 'torrentsTableMenu',
         actions: {
diff --git a/src/webui/www/private/upload.html b/src/webui/www/private/upload.html
index 4fa58c747..adbf64d94 100644
--- a/src/webui/www/private/upload.html
+++ b/src/webui/www/private/upload.html
@@ -127,7 +127,7 @@
     <script>
         'use strict';
 
-        var submitted = false;
+        let submitted = false;
 
         $('uploadForm').addEventListener("submit", function() {
             $('startTorrentHidden').value = $('startTorrent').checked ? 'false' : 'true';
diff --git a/src/webui/www/private/uploadlimit.html b/src/webui/www/private/uploadlimit.html
index f4c147596..b33ebaeea 100644
--- a/src/webui/www/private/uploadlimit.html
+++ b/src/webui/www/private/uploadlimit.html
@@ -24,9 +24,9 @@
         <script>
             'use strict';
 
-            var hashes = new URI().getData('hashes').split('|');
-            var setUpLimit = function() {
-                var limit = $("uplimitUpdatevalue").value.toInt() * 1024;
+            const hashes = new URI().getData('hashes').split('|');
+            const setUpLimit = function() {
+                const limit = $("uplimitUpdatevalue").value.toInt() * 1024;
                 if (hashes[0] == "global") {
                     new Request({
                         url: 'api/v2/transfer/setUploadLimit',
diff --git a/src/webui/www/public/scripts/login.js b/src/webui/www/public/scripts/login.js
index 518c2bf75..00cffccda 100644
--- a/src/webui/www/public/scripts/login.js
+++ b/src/webui/www/public/scripts/login.js
@@ -38,9 +38,9 @@ document.addEventListener('DOMContentLoaded', function() {
 });
 
 function submitLoginForm() {
-    var errorMsgElement = document.getElementById('error_msg');
+    const errorMsgElement = document.getElementById('error_msg');
 
-    var xhr = new XMLHttpRequest();
+    const xhr = new XMLHttpRequest();
     xhr.open('POST', 'api/v2/auth/login', true);
     xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded; charset=utf-8');
     xhr.addEventListener('readystatechange', function() {
@@ -57,9 +57,9 @@ function submitLoginForm() {
             : 'QBT_TR(Unable to log in, qBittorrent is probably unreachable.)QBT_TR[CONTEXT=HttpServer]';
     });
 
-    var usernameElement = document.getElementById('username');
-    var passwordElement = document.getElementById('password');
-    var queryString = "username=" + encodeURIComponent(usernameElement.value) + "&password=" + encodeURIComponent(passwordElement.value);
+    const usernameElement = document.getElementById('username');
+    const passwordElement = document.getElementById('password');
+    const queryString = "username=" + encodeURIComponent(usernameElement.value) + "&password=" + encodeURIComponent(passwordElement.value);
     xhr.send(queryString);
 
     // clear the field
diff --git a/src/webui/www/webui.qrc b/src/webui/www/webui.qrc
index ab36c2251..0e8270e93 100644
--- a/src/webui/www/webui.qrc
+++ b/src/webui/www/webui.qrc
@@ -18,6 +18,7 @@
         <file>private/index.html</file>
         <file>private/installsearchplugin.html</file>
         <file>private/newcategory.html</file>
+        <file>private/newtag.html</file>
         <file>private/preferences.html</file>
         <file>private/preferences_content.html</file>
         <file>private/properties.html</file>