diff --git a/client/src/cmdhfmfu.c b/client/src/cmdhfmfu.c
index 5620f7a64..93a6c5e10 100644
--- a/client/src/cmdhfmfu.c
+++ b/client/src/cmdhfmfu.c
@@ -2104,7 +2104,7 @@ void printMFUdumpEx(mfu_dump_t *card, uint16_t pages, uint8_t startpage) {
         PrintAndLogEx(INFO, "DYNAMIC LOCK: %s", sprint_hex(lockbytes_dyn, 3));
     }
 
-    for (uint8_t i = 0; i < pages; ++i) {
+    for (uint16_t i = 0; i < pages; ++i) {
         if (i < 3) {
             PrintAndLogEx(INFO, "%3d/0x%02X | %s|   | %s", i + startpage, i + startpage, sprint_hex(data + i * 4, 4), sprint_ascii(data + i * 4, 4));
             continue;
diff --git a/client/src/cmdlf.c b/client/src/cmdlf.c
index 9ecd3f6bf..0252c4736 100644
--- a/client/src/cmdlf.c
+++ b/client/src/cmdlf.c
@@ -174,7 +174,7 @@ static int CmdLFTune(const char *Cmd) {
     print_progress(0, max, style);
 
     // loop forever (till button pressed) if iter = 0 (default)
-    for (uint8_t i = 0; iter == 0 || i < iter; i++) {
+    for (uint32_t i = 0; iter == 0 || i < iter; i++) {
         if (kbd_enter_pressed()) {
             break;
         }
@@ -840,13 +840,13 @@ int lfsim_upload_gb(void) {
 
     //can send only 512 bits at a time (1 byte sent per bit...)
     PrintAndLogEx(INFO, "." NOLF);
-    for (uint16_t i = 0; i < g_GraphTraceLen; i += PM3_CMD_DATA_SIZE - 3) {
+    for (size_t i = 0; i < g_GraphTraceLen; i += PM3_CMD_DATA_SIZE - 3) {
 
         size_t len = MIN((g_GraphTraceLen - i), PM3_CMD_DATA_SIZE - 3);
         clearCommandBuffer();
         payload_up.offset = i;
 
-        for (uint16_t j = 0; j < len; j++)
+        for (size_t j = 0; j < len; j++)
             payload_up.data[j] = g_GraphBuffer[i + j];
 
         SendCommandNG(CMD_LF_UPLOAD_SIM_SAMPLES, (uint8_t *)&payload_up, sizeof(struct pupload));
diff --git a/client/src/cmdlfidteck.c b/client/src/cmdlfidteck.c
index b8cc30020..3dae4f0d1 100644
--- a/client/src/cmdlfidteck.c
+++ b/client/src/cmdlfidteck.c
@@ -201,7 +201,7 @@ static int CmdIdteckSim(const char *Cmd) {
     memset(bs, 0x00, sizeof(bs));
 
     uint8_t counter = 0;
-    for (int8_t i = 0; i < raw_len; i++) {
+    for (int32_t i = 0; i < raw_len; i++) {
         uint8_t tmp = raw[i];
         bs[counter++] = (tmp >> 7) & 1;
         bs[counter++] = (tmp >> 6) & 1;
diff --git a/client/src/cmdlfindala.c b/client/src/cmdlfindala.c
index e059c3db3..0a8a9bb16 100644
--- a/client/src/cmdlfindala.c
+++ b/client/src/cmdlfindala.c
@@ -586,7 +586,7 @@ static int CmdIndalaSim(const char *Cmd) {
     memset(bs, 0x00, sizeof(bs));
 
     uint8_t counter = 0;
-    for (int8_t i = 0; i < raw_len; i++) {
+    for (int32_t i = 0; i < raw_len; i++) {
         uint8_t tmp = raw[i];
         bs[counter++] = (tmp >> 7) & 1;
         bs[counter++] = (tmp >> 6) & 1;
diff --git a/client/src/cmdlfparadox.c b/client/src/cmdlfparadox.c
index 986ed64cd..511a8019e 100644
--- a/client/src/cmdlfparadox.c
+++ b/client/src/cmdlfparadox.c
@@ -102,7 +102,7 @@ int demodParadox(bool verbose) {
     uint8_t error = 0;
 
     // Remove manchester encoding from FSK bits, skip pre
-    for (uint8_t i = idx + PARADOX_PREAMBLE_LEN; i < (idx + 96); i += 2) {
+    for (uint32_t i = idx + PARADOX_PREAMBLE_LEN; i < (idx + 96); i += 2) {
 
         // not manchester data
         if (bits[i] == bits[i + 1]) {
diff --git a/client/src/cmdlft55xx.c b/client/src/cmdlft55xx.c
index 3dd1be167..e06d8a228 100644
--- a/client/src/cmdlft55xx.c
+++ b/client/src/cmdlft55xx.c
@@ -296,7 +296,7 @@ bool t55xxAcquireAndCompareBlock0(bool usepwd, uint32_t password, uint32_t known
             continue;
         }
 
-        for (uint16_t i = 0; i < g_DemodBufferLen - 32; i++) {
+        for (size_t i = 0; i < g_DemodBufferLen - 32; i++) {
             uint32_t tmp = PackBits(i, 32, g_DemodBuffer);
             if (tmp == known_block0) {
                 config.offset = i;
@@ -4091,7 +4091,7 @@ static int CmdT55xxSniff(const char *Cmd) {
                 // We auto find widths
                 if ((width0 == 0) && (width1 == 0)) {
                     // We ignore bit 0 for the moment as it may be a ref. pulse, so check last
-                    uint8_t ii = 2;
+                    uint32_t ii = 2;
                     minWidth = pulseBuffer[1];
                     maxWidth = pulseBuffer[1];
                     bool done = false;
diff --git a/client/src/cmdtrace.c b/client/src/cmdtrace.c
index acbc5e5ef..1dcf20c1f 100644
--- a/client/src/cmdtrace.c
+++ b/client/src/cmdtrace.c
@@ -35,7 +35,7 @@ static int CmdHelp(const char *Cmd);
 
 // trace pointer
 static uint8_t *gs_trace;
-static long gs_traceLen = 0;
+static uint16_t gs_traceLen = 0;
 
 static bool is_last_record(uint16_t tracepos, uint16_t traceLen) {
     return ((tracepos + TRACELOG_HDR_LEN) >= traceLen);
diff --git a/client/src/fileutils.c b/client/src/fileutils.c
index 2ac29b849..21c052550 100644
--- a/client/src/fileutils.c
+++ b/client/src/fileutils.c
@@ -1645,7 +1645,7 @@ static int filelist(const char *path, const char *ext, uint8_t last, bool tentat
 
     PrintAndLogEx(NORMAL, "%s── "_GREEN_("%s"), last ? "└" : "├", &path[strip]);
 
-    for (uint16_t i = 0; i < n; i++) {
+    for (int i = 0; i < n; i++) {
 
         char tmp_fullpath[1024] = {0};
         strncat(tmp_fullpath, path, sizeof(tmp_fullpath) - 1);
diff --git a/client/src/graph.c b/client/src/graph.c
index 9f87271fc..5914c8585 100644
--- a/client/src/graph.c
+++ b/client/src/graph.c
@@ -33,7 +33,7 @@ TODO,  verfy that this doesn't overflow buffer  (iceman)
 */
 void AppendGraph(bool redraw, uint16_t clock, int bit) {
     uint8_t half = clock / 2;
-    uint8_t i;
+    uint16_t i;
     //set first half the clock bit (all 1's or 0's for a 0 or 1 bit)
     for (i = 0; i < half; ++i)
         g_GraphBuffer[g_GraphTraceLen++] = bit;
diff --git a/client/src/loclass/cipherutils.c b/client/src/loclass/cipherutils.c
index eaca50325..eaeee3019 100644
--- a/client/src/loclass/cipherutils.c
+++ b/client/src/loclass/cipherutils.c
@@ -126,15 +126,13 @@ uint64_t x_bytes_to_num(uint8_t *src, size_t len) {
 }
 
 void reverse_arraybytes(uint8_t *arr, size_t len) {
-    uint8_t i;
-    for (i = 0; i < len ; i++) {
+    for (size_t i = 0; i < len ; i++) {
         arr[i] = reflect8(arr[i]);
     }
 }
 
 void reverse_arraycopy(uint8_t *arr, uint8_t *dest, size_t len) {
-    uint8_t i;
-    for (i = 0; i < len ; i++) {
+    for (size_t i = 0; i < len ; i++) {
         dest[i] = reflect8(arr[i]);
     }
 }
diff --git a/client/src/loclass/elite_crack.c b/client/src/loclass/elite_crack.c
index 4741e52ac..ec13ca76e 100644
--- a/client/src/loclass/elite_crack.c
+++ b/client/src/loclass/elite_crack.c
@@ -445,7 +445,7 @@ int bruteforceItem(loclass_dumpdata_t item, uint16_t keytable[]) {
 
     loclass_thread_arg_t args[loclass_tc];
     // init thread arguments
-    for (int i = 0; i < loclass_tc; i++) {
+    for (size_t i = 0; i < loclass_tc; i++) {
         args[i].thread_idx = i;
         args[i].numbytes_to_recover = numbytes_to_recover;
         args[i].endmask = 1 << 8 * numbytes_to_recover;
@@ -458,7 +458,7 @@ int bruteforceItem(loclass_dumpdata_t item, uint16_t keytable[]) {
 
     pthread_t threads[loclass_tc];
     // create threads
-    for (int i = 0; i < loclass_tc; i++) {
+    for (size_t i = 0; i < loclass_tc; i++) {
         int res = pthread_create(&threads[i], NULL, bf_thread, (void *)&args[i]);
         if (res) {
             PrintAndLogEx(NORMAL, "");
@@ -468,7 +468,7 @@ int bruteforceItem(loclass_dumpdata_t item, uint16_t keytable[]) {
     }
     // wait for threads to terminate:
     void *ptrs[loclass_tc];
-    for (int i = 0; i < loclass_tc; i++)
+    for (size_t i = 0; i < loclass_tc; i++)
         pthread_join(threads[i], &ptrs[i]);
 
     // was it a success?
@@ -493,7 +493,7 @@ int bruteforceItem(loclass_dumpdata_t item, uint16_t keytable[]) {
             keytable[bytes_to_recover[i]] &= 0xFF;
             keytable[bytes_to_recover[i]] |= LOCLASS_CRACKED;
         }
-        for (uint8_t i = 0; i < loclass_tc; i++) {
+        for (size_t i = 0; i < loclass_tc; i++) {
             free(ptrs[i]);
         }
     }
diff --git a/client/src/ui.c b/client/src/ui.c
index b5b1fc0f4..74557cd5a 100644
--- a/client/src/ui.c
+++ b/client/src/ui.c
@@ -426,7 +426,7 @@ void memcpy_filter_rlmarkers(void *dest, const void *src, size_t n) {
     uint8_t *rdest = (uint8_t *)dest;
     uint8_t *rsrc = (uint8_t *)src;
     uint16_t si = 0;
-    for (uint16_t i = 0; i < n; i++) {
+    for (size_t i = 0; i < n; i++) {
         if ((rsrc[i] == '\001') || (rsrc[i] == '\002'))
             // skip readline special markers
             continue;
@@ -440,7 +440,7 @@ void memcpy_filter_ansi(void *dest, const void *src, size_t n, bool filter) {
         uint8_t *rdest = (uint8_t *)dest;
         uint8_t *rsrc = (uint8_t *)src;
         uint16_t si = 0;
-        for (uint16_t i = 0; i < n; i++) {
+        for (size_t i = 0; i < n; i++) {
             if ((i < n - 1)
                     && (rsrc[i] == '\x1b')
                     && (rsrc[i + 1] >= 0x40)
@@ -531,7 +531,7 @@ void memcpy_filter_emoji(void *dest, const void *src, size_t n, emojiMode_t mode
         char *rdest = (char *)dest;
         char *rsrc = (char *)src;
         uint16_t si = 0;
-        for (uint16_t i = 0; i < n; i++) {
+        for (size_t i = 0; i < n; i++) {
             current_char = rsrc[i];
 
             if (current_token_length == 0) {
diff --git a/client/src/util.c b/client/src/util.c
index 103521b42..bb517b5bb 100644
--- a/client/src/util.c
+++ b/client/src/util.c
@@ -280,8 +280,8 @@ void print_blocks(uint32_t *data, size_t len) {
     if (!data) {
         PrintAndLogEx(ERR, "..empty data");
     } else {
-        for (uint8_t i = 0; i < len; i++)
-            PrintAndLogEx(SUCCESS, " %02d | %08X", i, data[i]);
+        for (size_t i = 0; i < len; i++)
+            PrintAndLogEx(SUCCESS, " %02zd | %08X", i, data[i]);
     }
 }
 
diff --git a/common/crc.c b/common/crc.c
index 876c00951..016d8e5be 100644
--- a/common/crc.c
+++ b/common/crc.c
@@ -163,7 +163,7 @@ uint32_t CRC8Hitag1Bits(const uint8_t *buff, size_t bitsize) {
     uint8_t data = 0;
     uint8_t n = 0;
     crc_init_ref(&crc, 8, 0x1d, 0xff, 0, false, false);
-    uint8_t i;
+    size_t i;
     for (i = 0; i < bitsize; i++) {
         data <<= 1;
         data += (buff[i / 8] >> (7 - (i % 8))) & 1;
diff --git a/common/lfdemod.c b/common/lfdemod.c
index 6401d522c..bf0bfd4c6 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -701,7 +701,7 @@ int DetectASKClock(uint8_t *dest, size_t size, int *clock, int maxErr) {
     }
 
     size_t i = 1;
-    uint16_t num_clks = 9;
+    uint8_t num_clks = 9;
     // first 255 value pos0 is placeholder for user inputed clock.
     uint16_t clk[] = {255, 8, 16, 32, 40, 50, 64, 100, 128, 255};