diff --git a/CHANGELOG.md b/CHANGELOG.md
index 01c64b5b7..50a0f8fef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ All notable changes to this project will be documented in this file.
 - ESP32 Platform from 2024.11.30 to 2024.11.31, Framework (Arduino Core) from v3.1.0.241030 to v3.1.0.241117 and IDF to 5.3.1.241024 (#22504)
 
 ### Fixed
+- ESP32 upgrade by file upload response based on file size (#22500)
 
 ### Removed
 
diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 297e99b85..ee2aaedf1 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -169,6 +169,7 @@ The latter links can be used for OTA upgrades too like ``OtaUrl https://ota.tasm
 - Mitsubishi Electric HVAC Standby Stage for MiElHVAC [#22430](https://github.com/arendst/Tasmota/issues/22430)
 - EQ3 TRV firmware version 1.46 fails if the default true is used in subscribe on the notify characteristic [#22328](https://github.com/arendst/Tasmota/issues/22328)
 - Ethernet on -DFRAMEWORK_ARDUINO_ITEAD framework regression from v14.3.0 [#22367](https://github.com/arendst/Tasmota/issues/22367)
+- ESP32 Upgrade by file upload response based on file size [#22500](https://github.com/arendst/Tasmota/issues/22500)
 - ESP32 Arduino Core IPv6 zones used by Matter [#22378](https://github.com/arendst/Tasmota/issues/22378)
 - ESP32, ESP32-S2 and ESP32-S3 re-enable touch buttons [#22446](https://github.com/arendst/Tasmota/issues/22446)
 - ESP32-S3 UART output mode for Tx [#22426](https://github.com/arendst/Tasmota/issues/22426)
diff --git a/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino b/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino
index a7ad95d34..856c9a46d 100644
--- a/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_01_9_webserver.ino
@@ -368,23 +368,32 @@ const char HTTP_FORM_UPG[] PROGMEM =
   "<br><button type='submit'>" D_START_UPGRADE "</button></form>"
   "</fieldset><br><br>"
   "<fieldset><legend><b>&nbsp;" D_UPGRADE_BY_FILE_UPLOAD "&nbsp;</b></legend>";
-const char HTTP_FORM_RST_UPG[] PROGMEM =
+const char HTTP_FORM_RST_UPG[] PROGMEM =                  // ESP8266 or ESP32 dual partition
   "<form method='post' action='u2?fsz=' enctype='multipart/form-data'>"
   "<br><input type='file' name='u2'><br>"
   "<br><button type='submit' "
-  "onclick='eb(\"f1\").style.display=\"none\";eb(\"f2\").style.display=\"block\";this.form.action+=this.form[\"u2\"].files[0].size;this.form.submit();'"
-    ">%s</button></form>"
+  "onclick='"
+    "eb(\"f1\").style.display=\"none\";"                  // Disable display of form f1
+    "eb(\"f2\").style.display=\"block\";"                 // Enable display of D_UPLOAD_STARTED
+    "this.form.action+=this.form[\"u2\"].files[0].size;"  // Set return file size
+    "this.form.submit();"                                 // Form response
+  "'>%s</button></form>"
   "</fieldset>"
   "</div>"
   "<div id='f2' style='display:none;text-align:center;'><b>" D_UPLOAD_STARTED "...</b></div>";
 
 // upload via factory partition
-const char HTTP_FORM_RST_UPG_FCT[] PROGMEM =
+const char HTTP_FORM_RST_UPG_FCT[] PROGMEM =              // ESP32 safeboot partition
   "<form method='post' action='u2?fsz=' enctype='multipart/form-data'>"
   "<br><input type='file' name='u2'><br>"
   "<br><button type='submit' "
-  "onclick='eb(\"f1\").style.display=\"none\";eb(\"f3\").style.display=\"block\";this.form.action+=this.form[\"u2\"].files[0].size;return upl(this);'"
-    ">%s</button></form>"
+  "onclick='"
+    "eb(\"f1\").style.display=\"none\";"                  // Disable display of form f1
+    "var fs=this.form[\"u2\"].files[0].size;"             // Retreive file size of requested file
+    "eb((fs>900000)?\"f3\":\"f2\").style.display=\"block\";"  // Enable display of either D_UPLOAD_FACTORY or D_UPLOAD_STARTED based on arbitrary file size of 900k
+    "this.form.action+=fs;"                               // Set return file size
+    "return upl(this);"                                   // Form response
+  "'>%s</button></form>"
   "</fieldset>"
   "</div>"
   "<div id='f3' style='display:none;text-align:center;'><b>" D_UPLOAD_FACTORY "...</b></div>"