diff --git a/client/cmddata.c b/client/cmddata.c
index d971d0fba..9b637894d 100644
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -1985,7 +1985,7 @@ static void GetHiLoTone(int *LowTone, int *HighTone, int clk, int LowToneFC, int
 
 //old CmdFSKdemod adapted by marshmellow
 //converts FSK to clear NRZ style wave.  (or demodulates)
-static int FSKToNRZ(int *data, int *dataLen, int clk, int LowToneFC, int HighToneFC) {
+static int FSKToNRZ(int *data, size_t *dataLen, int clk, int LowToneFC, int HighToneFC) {
     uint8_t ans = 0;
     if (clk == 0 || LowToneFC == 0 || HighToneFC == 0) {
         int firstClockEdge = 0;
@@ -2002,17 +2002,16 @@ static int FSKToNRZ(int *data, int *dataLen, int clk, int LowToneFC, int HighTon
         return 0;
     }
 
-    int i, j;
     int LowTone[clk];
     int HighTone[clk];
     GetHiLoTone(LowTone, HighTone, clk, LowToneFC, HighToneFC);
 
     // loop through ([all samples] - clk)
-    for (i = 0; i < *dataLen - clk; ++i) {
+    for (size_t i = 0; i < *dataLen - clk; ++i) {
         int lowSum = 0, highSum = 0;
 
         // sum all samples together starting from this sample for [clk] samples for each tone (multiply tone value with sample data)
-        for (j = 0; j < clk; ++j) {
+        for (size_t j = 0; j < clk; ++j) {
             lowSum += LowTone[j] * data[i + j];
             highSum += HighTone[j] * data[i + j];
         }
@@ -2026,14 +2025,14 @@ static int FSKToNRZ(int *data, int *dataLen, int clk, int LowToneFC, int HighTon
     // now we have the abs( [average sample value per clk] * 100 ) for each tone
     //   loop through again [all samples] - clk - 16
     //                  note why 16???  is 16 the largest FC? changed to LowToneFC as that should be the > fc
-    for (i = 0; i < *dataLen - clk - LowToneFC; ++i) {
+    for (size_t i = 0; i < *dataLen - clk - LowToneFC; ++i) {
         int lowTot = 0, highTot = 0;
 
         // sum a field clock width of abs( [average sample values per clk] * 100) for each tone
-        for (j = 0; j < LowToneFC; ++j) {  //10 for fsk2
+        for (size_t j = 0; j < LowToneFC; ++j) {  //10 for fsk2
             lowTot += (data[i + j] & 0xffff);
         }
-        for (j = 0; j < HighToneFC; j++) {  //8 for fsk2
+        for (size_t j = 0; j < HighToneFC; j++) {  //8 for fsk2
             highTot += (data[i + j] >> 16);
         }
 
diff --git a/client/crypto/asn1dump.c b/client/crypto/asn1dump.c
index 2fd99ac40..e197749a0 100644
--- a/client/crypto/asn1dump.c
+++ b/client/crypto/asn1dump.c
@@ -165,7 +165,7 @@ static void asn1_tag_dump_string(const struct tlv *tlv, const struct asn1_tag *t
 
 static void asn1_tag_dump_octet_string(const struct tlv *tlv, const struct asn1_tag *tag, FILE *f, int level, bool *needdump) {
     *needdump = false;
-    for (int i = 0; i < tlv->len; i++)
+    for (size_t i = 0; i < tlv->len; i++)
         if (!isspace(tlv->value[i]) && !isprint(tlv->value[i])) {
             *needdump = true;
             break;
@@ -181,7 +181,7 @@ static void asn1_tag_dump_octet_string(const struct tlv *tlv, const struct asn1_
 
 static unsigned long asn1_value_integer(const struct tlv *tlv, unsigned start, unsigned end) {
     unsigned long ret = 0;
-    int i;
+    unsigned i;
 
     if (end > tlv->len * 2)
         return ret;
@@ -222,7 +222,7 @@ static void asn1_tag_dump_integer(const struct tlv *tlv, const struct asn1_tag *
     PRINT_INDENT(level);
     if (tlv->len == 4) {
         int32_t val = 0;
-        for (int i = 0; i < tlv->len; i++)
+        for (size_t i = 0; i < tlv->len; i++)
             val = (val << 8) + tlv->value[i];
         fprintf(f, "\tvalue4b: %d\n", val);
         return;
diff --git a/client/fido/fidocore.c b/client/fido/fidocore.c
index a688d9a9a..a10e6291e 100644
--- a/client/fido/fidocore.c
+++ b/client/fido/fidocore.c
@@ -150,7 +150,7 @@ fido2Desc_t fido2CmdGetInfoRespDesc[] = {
 };
 
 const char *fido2GetCmdErrorDescription(uint8_t errorCode) {
-    for (int i = 0; i < sizeof(fido2Errors) / sizeof(fido2Error_t); i++)
+    for (size_t i = 0; i < sizeof(fido2Errors) / sizeof(fido2Error_t); i++)
         if (fido2Errors[i].ErrorCode == errorCode)
             return fido2Errors[i].Description;
 
@@ -158,7 +158,7 @@ const char *fido2GetCmdErrorDescription(uint8_t errorCode) {
 }
 
 const char *fido2GetCmdMemberDescription(uint8_t cmdCode, bool isResponse, int memberNum) {
-    for (int i = 0; i < sizeof(fido2CmdGetInfoRespDesc) / sizeof(fido2Desc_t); i++)
+    for (size_t i = 0; i < sizeof(fido2CmdGetInfoRespDesc) / sizeof(fido2Desc_t); i++)
         if (fido2CmdGetInfoRespDesc[i].Command == cmdCode &&
                 fido2CmdGetInfoRespDesc[i].PckType == (isResponse ? ptResponse : ptQuery) &&
                 fido2CmdGetInfoRespDesc[i].MemberNumber == memberNum)
diff --git a/client/graph.c b/client/graph.c
index 677ab0846..d2a816125 100644
--- a/client/graph.c
+++ b/client/graph.c
@@ -10,7 +10,7 @@
 #include "graph.h"
 
 int GraphBuffer[MAX_GRAPH_TRACE_LEN];
-int GraphTraceLen;
+size_t GraphTraceLen;
 int s_Buff[MAX_GRAPH_TRACE_LEN];
 
 /* write a manchester bit to the graph
@@ -30,8 +30,8 @@ void AppendGraph(bool redraw, int clock, int bit) {
 }
 
 // clear out our graph window
-int ClearGraph(bool redraw) {
-    int gtl = GraphTraceLen;
+size_t ClearGraph(bool redraw) {
+    size_t gtl = GraphTraceLen;
     memset(GraphBuffer, 0x00, GraphTraceLen);
     GraphTraceLen = 0;
     if (redraw)
@@ -41,7 +41,7 @@ int ClearGraph(bool redraw) {
 // option '1' to save GraphBuffer any other to restore
 void save_restoreGB(uint8_t saveOpt) {
     static int SavedGB[MAX_GRAPH_TRACE_LEN];
-    static int SavedGBlen = 0;
+    static size_t SavedGBlen = 0;
     static bool GB_Saved = false;
     static int SavedGridOffsetAdj = 0;
 
@@ -67,7 +67,7 @@ void setGraphBuf(uint8_t *buff, size_t size) {
     if (size > MAX_GRAPH_TRACE_LEN)
         size = MAX_GRAPH_TRACE_LEN;
 
-    for (uint32_t i = 0; i < size; ++i)
+    for (size_t i = 0; i < size; ++i)
         GraphBuffer[i] = buff[i] - 128;
 
     GraphTraceLen = size;
@@ -77,7 +77,7 @@ void setGraphBuf(uint8_t *buff, size_t size) {
 
 size_t getFromGraphBuf(uint8_t *buff) {
     if (buff == NULL) return 0;
-    uint32_t i;
+    size_t i;
     for (i = 0; i < GraphTraceLen; ++i) {
         //trim
         if (GraphBuffer[i] > 127) GraphBuffer[i] = 127;
@@ -89,7 +89,7 @@ size_t getFromGraphBuf(uint8_t *buff) {
 
 // A simple test to see if there is any data inside Graphbuffer.
 bool HasGraphData() {
-    if (GraphTraceLen <= 0) {
+    if (GraphTraceLen == 0) {
         PrintAndLogEx(NORMAL, "No data available, try reading something first");
         return false;
     }
diff --git a/client/graph.h b/client/graph.h
index 98acec8dd..accd64de8 100644
--- a/client/graph.h
+++ b/client/graph.h
@@ -19,7 +19,7 @@
 #include "cmddata.h" //for g_debugmode
 
 void AppendGraph(bool redraw, int clock, int bit);
-int ClearGraph(bool redraw);
+size_t ClearGraph(bool redraw);
 size_t getFromGraphBuf(uint8_t *buff);
 int GetAskClock(const char *str, bool printAns);
 int GetPskClock(const char *str, bool printAns);
@@ -40,7 +40,7 @@ bool HasGraphData(void);
 #define GRAPH_RESTORE 0
 
 extern int GraphBuffer[MAX_GRAPH_TRACE_LEN];
-extern int GraphTraceLen;
+extern size_t GraphTraceLen;
 extern int s_Buff[MAX_GRAPH_TRACE_LEN];
 
 #endif
diff --git a/client/loclass/fileutils.c b/client/loclass/fileutils.c
index d85adc0c8..72d3e26af 100644
--- a/client/loclass/fileutils.c
+++ b/client/loclass/fileutils.c
@@ -92,7 +92,6 @@ int saveFileEML(const char *preferredName, const char *suffix, uint8_t *data, si
     int retval = 0;
     int blocks = datalen / blocksize;
     uint16_t currblock = 1;
-    int i, j;
     int size = sizeof(char) * (strlen(preferredName) + strlen(suffix) + 10);
     char *fileName = calloc(size, sizeof(char));
     int num = 1;
@@ -112,7 +111,7 @@ int saveFileEML(const char *preferredName, const char *suffix, uint8_t *data, si
         goto out;
     }
 
-    for (i = 0; i < datalen; i++) {
+    for (size_t i = 0; i < datalen; i++) {
         fprintf(f, "%02X", data[i]);
 
         // no extra line in the end
@@ -124,7 +123,7 @@ int saveFileEML(const char *preferredName, const char *suffix, uint8_t *data, si
     // left overs
     if (datalen % blocksize != 0) {
         int index = blocks * blocksize;
-        for (j = 0; j < datalen % blocksize; j++) {
+        for (size_t j = 0; j < datalen % blocksize; j++) {
             fprintf(f, "%02X", data[index + j]);
         }
     }
@@ -162,9 +161,9 @@ int saveFileJSON(const char *preferredName, const char *suffix, JSONFileType fty
         }
         case jsfCardMemory: {
             JsonSaveStr(root, "FileType", "mfcard");
-            for (int i = 0; i < (datalen / 16); i++) {
+            for (size_t i = 0; i < (datalen / 16); i++) {
                 char path[PATH_MAX_LENGTH] = {0};
-                sprintf(path, "$.blocks.%d", i);
+                sprintf(path, "$.blocks.%zu", i);
                 JsonSaveBufAsHexCompact(root, path, &data[i * 16], 16);
 
                 if (i == 0) {
@@ -188,19 +187,19 @@ int saveFileJSON(const char *preferredName, const char *suffix, JSONFileType fty
                     JsonSaveBufAsHexCompact(root, path, &data[i * 16 + 6], 4);
 
                     memset(path, 0x00, sizeof(path));
-                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%d", mfSectorNum(i), i - 3);
+                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%zu", mfSectorNum(i), i - 3);
                     JsonSaveStr(root, path, mfGetAccessConditionsDesc(0, adata));
 
                     memset(path, 0x00, sizeof(path));
-                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%d", mfSectorNum(i), i - 2);
+                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%zu", mfSectorNum(i), i - 2);
                     JsonSaveStr(root, path, mfGetAccessConditionsDesc(1, adata));
 
                     memset(path, 0x00, sizeof(path));
-                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%d", mfSectorNum(i), i - 1);
+                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%zu", mfSectorNum(i), i - 1);
                     JsonSaveStr(root, path, mfGetAccessConditionsDesc(2, adata));
 
                     memset(path, 0x00, sizeof(path));
-                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%d", mfSectorNum(i), i);
+                    sprintf(path, "$.SectorKeys.%d.AccessConditionsText.block%zu", mfSectorNum(i), i);
                     JsonSaveStr(root, path, mfGetAccessConditionsDesc(3, adata));
 
                     memset(path, 0x00, sizeof(path));
@@ -231,9 +230,9 @@ int saveFileJSON(const char *preferredName, const char *suffix, JSONFileType fty
             // size of header 48b
             size_t len = (datalen - DUMP_PREFIX_LENGTH) / 4;
 
-            for (int i = 0; i < len; i++) {
+            for (size_t i = 0; i < len; i++) {
                 char path[PATH_MAX_LENGTH] = {0};
-                sprintf(path, "$.blocks.%d", i);
+                sprintf(path, "$.blocks.%zu", i);
                 JsonSaveBufAsHexCompact(root, path, tmp->data + (i * 4), 4);
             }
             break;
@@ -245,9 +244,9 @@ int saveFileJSON(const char *preferredName, const char *suffix, JSONFileType fty
 
             JsonSaveBufAsHexCompact(root, "$.Card.UID", uid, sizeof(uid));
 
-            for (int i = 0; i < (datalen / 4); i++) {
+            for (size_t i = 0; i < (datalen / 4); i++) {
                 char path[PATH_MAX_LENGTH] = {0};
-                sprintf(path, "$.blocks.%d", i);
+                sprintf(path, "$.blocks.%zu", i);
                 JsonSaveBufAsHexCompact(root, path, data + (i * 4), 4);
             }
             break;
@@ -470,14 +469,14 @@ int loadFileJSON(const char *preferredName, const char *suffix, void *data, size
 
     if (!strcmp(ctype, "hitag")) {
         size_t sptr = 0;
-        for (int i = 0; i < (maxdatalen / 4); i++) {
+        for (size_t i = 0; i < (maxdatalen / 4); i++) {
             if (sptr + 4 > maxdatalen) {
                 retval = 5;
                 goto out;
             }
 
             char path[30] = {0};
-            sprintf(path, "$.blocks.%d", i);
+            sprintf(path, "$.blocks.%zu", i);
 
             size_t len = 0;
             JsonLoadBufAsHex(root, path, &udata[sptr], 4, &len);
diff --git a/client/mifare/mfkey.c b/client/mifare/mfkey.c
index b55c7e3c7..3ce2975b9 100644
--- a/client/mifare/mfkey.c
+++ b/client/mifare/mfkey.c
@@ -27,7 +27,7 @@ uint32_t intersection(uint64_t *listA, uint64_t *listB) {
     p1 = p3 = listA;
     p2 = listB;
 
-    while (*p1 != -1 && *p2 != -1) {
+    while (*p1 != UINT64_C(-1) && *p2 != UINT64_C(-1)) {
         if (compare_uint64(p1, p2) == 0) {
             *p3++ = *p1++;
             p2++;
@@ -36,7 +36,7 @@ uint32_t intersection(uint64_t *listA, uint64_t *listB) {
             while (compare_uint64(p1, p2) > 0) ++p2;
         }
     }
-    *p3 = -1;
+    *p3 = UINT64_C(-1);
     return p3 - listA;
 }
 
diff --git a/client/mifare/mifarehost.c b/client/mifare/mifarehost.c
index 0b2a49048..b7842dda0 100644
--- a/client/mifare/mifarehost.c
+++ b/client/mifare/mifarehost.c
@@ -89,13 +89,13 @@ int mfDarkside(uint8_t blockno, uint8_t key_type, uint64_t *key) {
 
         PrintAndLogEx(SUCCESS, "found %u candidate key%s\n", keycount, (keycount > 1) ? "s." : ".");
 
-        *key = -1;
+        *key = UINT64_C(-1);
         uint8_t keyBlock[USB_CMD_DATA_SIZE];
-        int max_keys = USB_CMD_DATA_SIZE / 6;
-        for (int i = 0; i < keycount; i += max_keys) {
+        uint32_t max_keys = USB_CMD_DATA_SIZE / 6;
+        for (uint32_t i = 0; i < keycount; i += max_keys) {
 
-            int size = keycount - i > max_keys ? max_keys : keycount - i;
-            for (int j = 0; j < size; j++) {
+            uint32_t size = keycount - i > max_keys ? max_keys : keycount - i;
+            for (uint32_t j = 0; j < size; j++) {
                 if (par_list == 0) {
                     num_to_bytes(last_keylist[i * max_keys + j], 6, keyBlock + (j * 6));
                 } else {
@@ -108,7 +108,7 @@ int mfDarkside(uint8_t blockno, uint8_t key_type, uint64_t *key) {
             }
         }
 
-        if (*key != -1) {
+        if (*key != UINT64_C(-1)) {
             break;
         } else {
             PrintAndLogEx(FAILED, "all candidate keys failed. Restarting darkside attack");
diff --git a/client/proxgui.h b/client/proxgui.h
index 613f793d1..2c0cf0601 100644
--- a/client/proxgui.h
+++ b/client/proxgui.h
@@ -28,11 +28,12 @@ void ExitGraphics(void);
 #define MAX_GRAPH_TRACE_LEN (40000 * 8)
 #endif
 extern int GraphBuffer[MAX_GRAPH_TRACE_LEN];
-extern int GraphTraceLen;
+extern size_t GraphTraceLen;
 extern int s_Buff[MAX_GRAPH_TRACE_LEN];
 
 extern double CursorScaleFactor;
-extern int PlotGridX, PlotGridY, PlotGridXdefault, PlotGridYdefault, CursorCPos, CursorDPos, GridOffset;
+extern int PlotGridX, PlotGridY, PlotGridXdefault, PlotGridYdefault, GridOffset;
+extern uint32_t CursorCPos, CursorDPos;
 extern int CommandFinished;
 extern int offline;
 extern bool GridLocked;
diff --git a/client/proxguiqt.cpp b/client/proxguiqt.cpp
index 102b006ce..2cf2d0200 100644
--- a/client/proxguiqt.cpp
+++ b/client/proxguiqt.cpp
@@ -33,7 +33,7 @@ extern "C" {
 
 bool g_useOverlays = false;
 int g_absVMax = 0;
-int startMax;
+uint32_t startMax;
 int PageWidth;
 int unlockStart = 0;
 
@@ -274,7 +274,7 @@ QColor Plot::getColor(int graphNum) {
     }
 }
 
-void Plot::setMaxAndStart(int *buffer, int len, QRect plotRect) {
+void Plot::setMaxAndStart(int *buffer, size_t len, QRect plotRect) {
     if (len == 0) return;
     startMax = (len - (int)((plotRect.right() - plotRect.left() - 40) / GraphPixelsPerPoint));
     if (startMax < 0) {
@@ -285,7 +285,7 @@ void Plot::setMaxAndStart(int *buffer, int len, QRect plotRect) {
     }
     if (GraphStart > len) return;
     int vMin = INT_MAX, vMax = INT_MIN, v = 0;
-    int sample_index = GraphStart ;
+    uint32_t sample_index = GraphStart ;
     for (; sample_index < len && xCoordOf(sample_index, plotRect) < plotRect.right() ; sample_index++) {
 
         v = buffer[sample_index];
@@ -299,7 +299,7 @@ void Plot::setMaxAndStart(int *buffer, int len, QRect plotRect) {
     g_absVMax = (int)(g_absVMax * 1.25 + 1);
 }
 
-void Plot::PlotDemod(uint8_t *buffer, size_t len, QRect plotRect, QRect annotationRect, QPainter *painter, int graphNum, int plotOffset) {
+void Plot::PlotDemod(uint8_t *buffer, size_t len, QRect plotRect, QRect annotationRect, QPainter *painter, int graphNum, uint32_t plotOffset) {
     if (len == 0 || PlotGridX <= 0) return;
     //clock_t begin = clock();
     QPainterPath penPath;
@@ -354,11 +354,12 @@ void Plot::PlotDemod(uint8_t *buffer, size_t len, QRect plotRect, QRect annotati
     painter->drawPath(penPath);
 }
 
-void Plot::PlotGraph(int *buffer, int len, QRect plotRect, QRect annotationRect, QPainter *painter, int graphNum) {
+void Plot::PlotGraph(int *buffer, size_t len, QRect plotRect, QRect annotationRect, QPainter *painter, int graphNum) {
     if (len == 0) return;
     // clock_t begin = clock();
     QPainterPath penPath;
-    int vMin = INT_MAX, vMax = INT_MIN, vMean = 0, v = 0, i = 0;
+    int vMin = INT_MAX, vMax = INT_MIN, vMean = 0, v = 0;
+    uint32_t i = 0;
     int x = xCoordOf(GraphStart, plotRect);
     int y = yCoordOf(buffer[GraphStart], plotRect, g_absVMax);
     penPath.moveTo(x, y);
@@ -416,7 +417,7 @@ void Plot::PlotGraph(int *buffer, int len, QRect plotRect, QRect annotationRect,
     //Graph annotations
     painter->drawPath(penPath);
     char str[200];
-    sprintf(str, "max=%d  min=%d  mean=%d  n=%d/%d  CursorAVal=[%d]  CursorBVal=[%d]",
+    sprintf(str, "max=%d  min=%d  mean=%d  n=%d/%zu  CursorAVal=[%d]  CursorBVal=[%d]",
             vMax, vMin, vMean, i, len, buffer[CursorAPos], buffer[CursorBPos]);
     painter->drawText(20, annotationRect.bottom() - 23 - 20 * graphNum, str);
 
diff --git a/client/proxguiqt.h b/client/proxguiqt.h
index fd6e00f13..6d92c22e7 100644
--- a/client/proxguiqt.h
+++ b/client/proxguiqt.h
@@ -31,17 +31,17 @@ class ProxWidget;
 class Plot: public QWidget {
   private:
     QWidget *master;
-    int GraphStart;
+    uint32_t GraphStart;
     double GraphPixelsPerPoint;
-    int CursorAPos;
-    int CursorBPos;
-    void PlotGraph(int *buffer, int len, QRect r, QRect r2, QPainter *painter, int graphNum);
-    void PlotDemod(uint8_t *buffer, size_t len, QRect r, QRect r2, QPainter *painter, int graphNum, int plotOffset);
+    uint32_t CursorAPos;
+    uint32_t CursorBPos;
+    void PlotGraph(int *buffer, size_t len, QRect r, QRect r2, QPainter *painter, int graphNum);
+    void PlotDemod(uint8_t *buffer, size_t len, QRect r, QRect r2, QPainter *painter, int graphNum, uint32_t plotOffset);
     void plotGridLines(QPainter *painter, QRect r);
     int xCoordOf(int i, QRect r);
     int yCoordOf(int v, QRect r, int maxVal);
     int valueOf_yCoord(int y, QRect r, int maxVal);
-    void setMaxAndStart(int *buffer, int len, QRect plotRect);
+    void setMaxAndStart(int *buffer, size_t len, QRect plotRect);
     QColor getColor(int graphNum);
 
   public:
diff --git a/client/proxmark3.c b/client/proxmark3.c
index 2794099c6..600d975e3 100644
--- a/client/proxmark3.c
+++ b/client/proxmark3.c
@@ -298,7 +298,7 @@ int main(int argc, char *argv[]) {
         return 1;
     }
 
-    uint32_t i = 1;
+    int i = 1;
     port = argv[i++];
     for (; i < argc; i++) {
 
diff --git a/client/ui.c b/client/ui.c
index c72b46806..2725fe093 100644
--- a/client/ui.c
+++ b/client/ui.c
@@ -18,7 +18,8 @@
 #include "ui.h"
 
 double CursorScaleFactor = 1;
-int PlotGridX = 0, PlotGridY = 0, PlotGridXdefault = 64, PlotGridYdefault = 64, CursorCPos = 0, CursorDPos = 0;
+int PlotGridX = 0, PlotGridY = 0, PlotGridXdefault = 64, PlotGridYdefault = 64;
+uint32_t CursorCPos = 0, CursorDPos = 0;
 bool flushAfterWrite = 0;
 int GridOffset = 0;
 bool GridLocked = false;
@@ -33,13 +34,13 @@ void PrintAndLogOptions(const char *str[][2], size_t size, size_t space) {
     char buff[2000] = "Options:\n";
     char format[2000] = "";
     size_t counts[2] = {0, 0};
-    for (int i = 0; i < size; i++)
-        for (int j = 0 ; j < 2 ; j++)
+    for (size_t i = 0; i < size; i++)
+        for (size_t j = 0 ; j < 2 ; j++)
             if (counts[j] < strlen(str[i][j])) {
                 counts[j] = strlen(str[i][j]);
             }
-    for (int i = 0; i < size; i++) {
-        for (int j = 0; j < 2; j++) {
+    for (size_t i = 0; i < size; i++) {
+        for (size_t j = 0; j < 2; j++) {
             if (j == 0)
                 snprintf(format, sizeof(format), "%%%zus%%%zus", space, counts[j]);
             else
@@ -203,8 +204,6 @@ void SetFlushAfterWrite(bool value) {
 
 void iceIIR_Butterworth(int *data, const size_t len) {
 
-    int i, j;
-
     int *output = (int *) calloc(sizeof(int) * len, sizeof(uint8_t));
     if (!output) return;
 
@@ -219,7 +218,7 @@ void iceIIR_Butterworth(int *data, const size_t len) {
     float b[3] = {0.003621681514929,  0.007243363029857, 0.003621681514929};
     float a[3] = {1.000000000000000, -1.822694925196308, 0.837181651256023};
 
-    for (i = 0; i < adjustedLen; ++i) {
+    for (size_t i = 0; i < adjustedLen; ++i) {
 
         float sample = data[i];          // input sample read from array
         float complex x_prime  = 1.0f;   // save sample for estimating frequency
@@ -246,7 +245,7 @@ void iceIIR_Butterworth(int *data, const size_t len) {
 
     // show data
     //memcpy(data, output, adjustedLen);
-    for (j = 0; j < adjustedLen; ++j)
+    for (size_t j = 0; j < adjustedLen; ++j)
         data[j] = output[j];
 
     free(output);
@@ -260,7 +259,7 @@ void iceSimple_Filter(int *data, const size_t len, uint8_t k) {
     int32_t filter_reg = 0;
     int8_t shift = (k <= 8) ? k : FILTER_SHIFT;
 
-    for (int i = 0; i < len; ++i) {
+    for (size_t i = 0; i < len; ++i) {
         // Update filter with current sample
         filter_reg = filter_reg - (filter_reg >> shift) + data[i];
 
diff --git a/client/ui.h b/client/ui.h
index ca235c11f..574881918 100644
--- a/client/ui.h
+++ b/client/ui.h
@@ -41,7 +41,8 @@ void SetLogFilename(char *fn);
 void SetFlushAfterWrite(bool value);
 
 extern double CursorScaleFactor;
-extern int PlotGridX, PlotGridY, PlotGridXdefault, PlotGridYdefault, CursorCPos, CursorDPos, GridOffset;
+extern int PlotGridX, PlotGridY, PlotGridXdefault, PlotGridYdefault, GridOffset;
+extern uint32_t CursorCPos, CursorDPos;
 extern bool GridLocked;
 extern bool showDemod;
 
diff --git a/client/util.c b/client/util.c
index a71f79ffd..05e9d700c 100644
--- a/client/util.c
+++ b/client/util.c
@@ -160,7 +160,7 @@ int FillBuffer(uint8_t *data, size_t maxDataLength, size_t *dataLength, ...) {
 }
 
 bool CheckStringIsHEXValue(const char *value) {
-    for (int i = 0; i < strlen(value); i++)
+    for (size_t i = 0; i < strlen(value); i++)
         if (!isxdigit(value[i]))
             return false;
 
@@ -177,17 +177,17 @@ void hex_to_buffer(const uint8_t *buf, const uint8_t *hex_data, const size_t hex
     size_t i;
     memset(tmp, 0x00, hex_max_len);
 
-    int maxLen = (hex_len > hex_max_len) ? hex_max_len : hex_len;
+    size_t maxLen = (hex_len > hex_max_len) ? hex_max_len : hex_len;
 
     for (i = 0; i < maxLen; ++i, tmp += 2 + spaces_between) {
         sprintf(tmp, (uppercase) ? "%02X" : "%02x", (unsigned int) hex_data[i]);
 
-        for (int j = 0; j < spaces_between; j++)
+        for (size_t j = 0; j < spaces_between; j++)
             sprintf(tmp + 2 + j, " ");
     }
 
     i *= (2 + spaces_between);
-    int minStrLen = min_str_len > i ? min_str_len : 0;
+    size_t minStrLen = min_str_len > i ? min_str_len : 0;
     if (minStrLen > hex_max_len)
         minStrLen = hex_max_len;
     for (; i < minStrLen; i++, tmp += 1)
@@ -198,8 +198,7 @@ void hex_to_buffer(const uint8_t *buf, const uint8_t *hex_data, const size_t hex
 
 // printing and converting functions
 void print_hex(const uint8_t *data, const size_t len) {
-    size_t i;
-    for (i = 0; i < len; i++)
+    for (size_t i = 0; i < len; i++)
         printf("%02x ", data[i]);
     printf("\n");
 }
@@ -207,7 +206,7 @@ void print_hex(const uint8_t *data, const size_t len) {
 void print_hex_break(const uint8_t *data, const size_t len, uint8_t breaks) {
     int rownum = 0;
     printf("[%02d] | ", rownum);
-    for (int i = 0; i < len; ++i) {
+    for (size_t i = 0; i < len; ++i) {
 
         printf("%02X ", data[i]);
 
@@ -246,7 +245,7 @@ char *sprint_bin_break(const uint8_t *data, const size_t len, const uint8_t brea
     // make sure we don't go beyond our char array memory
     size_t in_index = 0, out_index = 0;
 
-    int rowlen = (len > MAX_BIN_BREAK_LENGTH) ? MAX_BIN_BREAK_LENGTH : len;
+    size_t rowlen = (len > MAX_BIN_BREAK_LENGTH) ? MAX_BIN_BREAK_LENGTH : len;
 
     if (breaks > 0 && len % breaks != 0)
         rowlen = (len + (len / breaks) > MAX_BIN_BREAK_LENGTH) ? MAX_BIN_BREAK_LENGTH : len + (len / breaks);
@@ -351,7 +350,7 @@ char *sprint_ascii_ex(const uint8_t *data, const size_t len, const size_t min_st
         ++i;
     }
 
-    int m = min_str_len > i ? min_str_len : 0;
+    size_t m = min_str_len > i ? min_str_len : 0;
     for (; i < m; ++i)
         tmp[i] = ' ';
 
@@ -399,7 +398,7 @@ void num_to_bytebits(uint64_t n, size_t len, uint8_t *dest) {
 
 //least significant bit first
 void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest) {
-    for (int i = 0 ; i < len ; ++i) {
+    for (size_t i = 0 ; i < len ; ++i) {
         dest[i] =  n & 1;
         n >>= 1;
     }
@@ -876,7 +875,7 @@ int num_CPUs(void) {
 }
 
 void str_lower(char *s) {
-    for (int i = 0; i < strlen(s); i++)
+    for (size_t i = 0; i < strlen(s); i++)
         s[i] = tolower(s[i]);
 }
 bool str_startswith(const char *s,  const char *pre) {
diff --git a/common/crc.c b/common/crc.c
index c3bd90064..e197c0eee 100644
--- a/common/crc.c
+++ b/common/crc.c
@@ -94,7 +94,7 @@ static void print_crc(crc_t *crc) {
 uint32_t CRC8Maxim(uint8_t *buff, size_t size) {
     crc_t crc;
     crc_init_ref(&crc, 8, 0x31, 0, 0, true, true);
-    for (int i = 0; i < size; ++i)
+    for (size_t i = 0; i < size; ++i)
         crc_update2(&crc, buff[i], 8);
     return crc_finish(&crc);
 }
@@ -102,7 +102,7 @@ uint32_t CRC8Maxim(uint8_t *buff, size_t size) {
 uint32_t CRC8Mad(uint8_t *buff, size_t size) {
     crc_t crc;
     crc_init_ref(&crc, 8, 0x1d, 0xc7, 0, false, false);
-    for (int i = 0; i < size; ++i)
+    for (size_t i = 0; i < size; ++i)
         crc_update2(&crc, buff[i], 8);
     return crc_finish(&crc);
 }
@@ -120,7 +120,7 @@ uint32_t CRC4Legic(uint8_t *buff, size_t size) {
 uint32_t CRC8Legic(uint8_t *buff, size_t size) {
     crc_t crc;
     crc_init_ref(&crc, 8, 0x63, 0x55, 0, true, true);
-    for (int i = 0; i < size; ++i)
+    for (size_t i = 0; i < size; ++i)
         crc_update2(&crc, buff[i], 8);
     return reflect8(crc_finish(&crc));
 }
diff --git a/uart/uart_posix.c b/uart/uart_posix.c
index 2c1dc1b3b..8ea8aa619 100644
--- a/uart/uart_posix.c
+++ b/uart/uart_posix.c
@@ -231,7 +231,7 @@ void uart_close(const serial_port sp) {
 }
 
 bool uart_receive(const serial_port sp, uint8_t *pbtRx, size_t pszMaxRxLen, size_t *pszRxLen) {
-    int byteCount;
+    size_t byteCount;
     fd_set rfds;
     struct timeval tv;