diff --git a/src/OTAHTTPS.h b/src/OTAHTTPS.h
index e7d70a0..456cff3 100644
--- a/src/OTAHTTPS.h
+++ b/src/OTAHTTPS.h
@@ -16,7 +16,13 @@ __________           .___      .__  .__                 _____  .__       .__
 
 #include "Version.h"
 
-#define OTA_PARTITION_SIZE    0x1D0000      // 1900544 bytes
+#if defined(ARDUINO_BPI_LEAF_S3) || defined(ARDUINO_LILYGO_T_DISPLAY_S3)
+#define OTA_PARTITION_SIZE    0x360000            // 3538944 bytes
+#define FIRMWARE_MAX_SIZE     (8 * 1024 * 1024)   // 8M
+#else
+#define OTA_PARTITION_SIZE    0x1D0000            // 1900544 bytes
+#define FIRMWARE_MAX_SIZE     (4 * 1024 * 1024)   // 4M
+#endif
 
 String            latestFirmwareVersion = VERSION;
 String            url;
@@ -112,7 +118,7 @@ String get_latest_firmware_version(void) {
           DPRINT("[HTTPS] GET... code: %d\n", httpCode);
           // file found at server
           if (httpCode == HTTP_CODE_OK) {
-           payload = https.getString();
+            payload = https.getString();
             payload.trim();
             if (payload.equals(VERSION)) {
               DPRINT("Device already on latest firmware version: %s\n", VERSION);
@@ -135,6 +141,65 @@ String get_latest_firmware_version(void) {
 }
 
 
+String get_firmware_md5(void) {
+
+  String  payload = "";
+
+  if (!wifiEnabled) return payload;
+
+  WiFiClientSecure *client = new WiFiClientSecure;
+
+  if (client) {
+
+    client->setCACert(rootCACertificate);
+
+    {
+      // Add a scoping block for HTTPClient https to make sure it is destroyed before WiFiClientSecure *client is
+      HTTPClient https;
+
+      url = F("https://raw.githubusercontent.com/alf45tar/PedalinoMini/");
+      url += F(VERSION);
+      url += F("/firmware/");
+      url += xstr(PLATFORMIO_ENV);
+      url += F("/firmware.bin.md5?");
+      url += String(rand());
+
+      if (https.begin(*client, url)) {
+
+        DPRINT("[HTTPS] GET... %s\n", url.c_str());
+        // start connection and send HTTP header
+        int httpCode = https.GET();
+
+        // httpCode will be negative on error
+        if (httpCode > 0) {
+          // HTTP header has been send and Server response header has been handled
+          DPRINT("[HTTPS] GET... code: %d\n", httpCode);
+          // file found at server
+          if (httpCode == HTTP_CODE_OK) {
+            payload = https.getString();
+            payload.trim();
+          }
+        } else {
+          DPRINT("[HTTPS] GET... failed, error: %s\n", https.errorToString(httpCode).c_str());
+        }
+        https.end();
+      } else {
+        DPRINT("[HTTPS] Unable to connect\n");
+      }
+    }
+    delete client;
+  }
+
+  return payload;
+}
+
+
+bool official_firmware () {
+  String md5 = get_firmware_md5();
+  return md5.equals(sketchMD5);
+}
+
+
 void ota_https_update_event_handler(HttpEvent_t *event) {
 
     switch(event->event_id) {
@@ -165,9 +230,9 @@ void ota_https_update_event_handler(HttpEvent_t *event) {
             DPRINT("#");
             otaProgress += event->data_len;
 #if defined(ARDUINO_LILYGO_T_DISPLAY) || defined(ARDUINO_LILYGO_T_DISPLAY_S3)
-    display_progress_bar_update(otaProgress, OTA_PARTITION_SIZE);
+    display_progress_bar_update(otaProgress, FIRMWARE_MAX_SIZE);
 #else
-    display.drawProgressBar(4, 32, 120, 8, otaProgress / (OTA_PARTITION_SIZE / 100) );
+    display.drawProgressBar(4, 32, 120, 8, otaProgress / (FIRMWARE_MAX_SIZE / 100) );
     display.display();
 #endif
             break;
diff --git a/src/WebConfigAsync.h b/src/WebConfigAsync.h
index fe8fd09..ab7920e 100644
--- a/src/WebConfigAsync.h
+++ b/src/WebConfigAsync.h
@@ -4845,6 +4845,26 @@ void get_update_page(unsigned int start, unsigned int len) {
   page += F(" Update</button>");
   page += F("</div>");
   page += F("</div>");
+  page += F("<div class='row'>");
+  page += F("<div class='col-4'>");
+  page += F("<small>");
+  page += sketchMD5;
+  page += F("</small>");
+  page += F("</div>");
+  page += F("<div class='col-4'>");
+  page += F("<small>");
+  page += F("<div id='latestFirmwareVersion' w3-include-html='https://raw.githubusercontent.com/alf45tar/PedalinoMini/master/firmware/");
+  page += xstr(PLATFORMIO_ENV);
+  page += F("/firmware.bin.md5?");
+  page += (rand() % (999999 - 100000 + 1) + 100000);
+  page += F("'></div>");
+  page += F("</small>");
+  page += F("</div>");
+  page += F("<div class='col-1'>");
+  page += F("</div>");
+  page += F("<div class='col-3'>");
+  page += F("</div>");
+  page += F("</div>");
   page += F("</div>");
   page += F("</div>");
 
@@ -4864,7 +4884,9 @@ void get_update_page(unsigned int start, unsigned int len) {
   page += F("<input type='file' class='form-control' id='firmwareFile' name='upload'>");
   page += F("</div>");
   page += F("<small id='uploadHelpBlock' class='form-text text-muted'>");
-  page += F("Select firmware.bin or spiffs.bin and press Upload to upgrade firmware or file system image.");
+  page += F("Select firmware.bin or spiffs.bin and press Upload to upgrade firmware or file system image. Max file size is ");
+  page += FIRMWARE_MAX_SIZE;
+  page += F(" bytes.");
   page += F("</small>");
   page += F("</div>");
   page += F("<div class='col-1'>");
@@ -5060,7 +5082,7 @@ void get_update_page(unsigned int start, unsigned int len) {
 	              "const allowed_mime_types = [ 'application/octet-stream', 'application/macbinary' ];\n"
 
 	              "const allowed_size = ");
-  page += OTA_PARTITION_SIZE;
+  page += FIRMWARE_MAX_SIZE;
   page += F(";\n");
 
   if (trim_page(start, len)) return;
@@ -5071,7 +5093,7 @@ void get_update_page(unsigned int start, unsigned int len) {
                 "}\n"
 
 	              "if(file.size > allowed_size) {\n"
-		                "alert('File size exceeed 2M');\n"
+		                "alert('File size exceeed allowed size');\n"
 		                "return;"
 	              "}\n"
 
@@ -5447,7 +5469,7 @@ void http_handle_update(AsyncWebServerRequest *request) {
 
 void http_handle_progress(AsyncWebServerRequest *request) {
   if (firmwareUpdate == PED_UPDATE_CLOUD)
-    request->send(200, "text/plain", String(HttpsOTA.status() == HTTPS_OTA_UPDATING ? 100 * otaProgress / OTA_PARTITION_SIZE : 0));
+    request->send(200, "text/plain", String(HttpsOTA.status() == HTTPS_OTA_UPDATING ? 100 * otaProgress / FIRMWARE_MAX_SIZE : 0));
   else
     request->send(200, "text/plain", String(Update.isRunning() && Update.size() ? 100 * Update.progress() / Update.size() : 0));
 }