diff --git a/esphome/components/web_server_base/web_server_base.cpp b/esphome/components/web_server_base/web_server_base.cpp
index 1db6dc43e8..9bbeb7b605 100644
--- a/esphome/components/web_server_base/web_server_base.cpp
+++ b/esphome/components/web_server_base/web_server_base.cpp
@@ -119,8 +119,7 @@ void OTARequestHandler::handleUpload(AsyncWebServerRequest *request, const Strin
   // ESP-IDF implementation
   if (index == 0) {
     this->ota_init_(filename.c_str());
-    this->ota_started_ = false;
-    this->ota_success_ = false;
+    this->ota_state_ = OTAState::IDLE;
 
     // Create OTA backend
     auto backend = ota::make_ota_backend();
@@ -129,15 +128,16 @@ void OTARequestHandler::handleUpload(AsyncWebServerRequest *request, const Strin
     auto result = backend->begin(0);
     if (result != ota::OTA_RESPONSE_OK) {
       ESP_LOGE(TAG, "OTA begin failed: %d", result);
+      this->ota_state_ = OTAState::FAILED;
       return;
     }
 
     // Store the backend pointer
     this->ota_backend_ = backend.release();
-    this->ota_started_ = true;
+    this->ota_state_ = OTAState::STARTED;
   }
 
-  if (!this->ota_started_ || !this->ota_backend_) {
+  if (this->ota_state_ != OTAState::STARTED && this->ota_state_ != OTAState::IN_PROGRESS) {
     // Begin failed or was aborted
     return;
   }
@@ -145,6 +145,7 @@ void OTARequestHandler::handleUpload(AsyncWebServerRequest *request, const Strin
   // Write data
   if (len > 0) {
     auto *backend = static_cast<ota::OTABackend *>(this->ota_backend_);
+    this->ota_state_ = OTAState::IN_PROGRESS;
 
     auto result = backend->write(data, len);
     if (result != ota::OTA_RESPONSE_OK) {
@@ -152,8 +153,7 @@ void OTARequestHandler::handleUpload(AsyncWebServerRequest *request, const Strin
       backend->abort();
       delete backend;
       this->ota_backend_ = nullptr;
-      this->ota_started_ = false;
-      this->ota_success_ = false;
+      this->ota_state_ = OTAState::FAILED;
       return;
     }
 
@@ -165,15 +165,14 @@ void OTARequestHandler::handleUpload(AsyncWebServerRequest *request, const Strin
     auto *backend = static_cast<ota::OTABackend *>(this->ota_backend_);
     auto result = backend->end();
     if (result == ota::OTA_RESPONSE_OK) {
-      this->ota_success_ = true;
+      this->ota_state_ = OTAState::SUCCESS;
       this->schedule_ota_reboot_();
     } else {
       ESP_LOGE(TAG, "OTA end failed: %d", result);
-      this->ota_success_ = false;
+      this->ota_state_ = OTAState::FAILED;
     }
     delete backend;
     this->ota_backend_ = nullptr;
-    this->ota_started_ = false;
   }
 #endif  // USE_ESP_IDF
 #endif  // USE_WEBSERVER_OTA
@@ -195,7 +194,7 @@ void OTARequestHandler::handleRequest(AsyncWebServerRequest *request) {
 #ifdef USE_ESP_IDF
   // For ESP-IDF, we use direct send() instead of beginResponse()
   // to ensure the response is sent immediately before the reboot.
-  request->send(200, "text/plain", this->ota_success_ ? "Update Successful!" : "Update Failed!");
+  request->send(200, "text/plain", this->ota_state_ == OTAState::SUCCESS ? "Update Successful!" : "Update Failed!");
   return;
 #endif  // USE_ESP_IDF
   response->addHeader("Connection", "close");
diff --git a/esphome/components/web_server_base/web_server_base.h b/esphome/components/web_server_base/web_server_base.h
index d6be110582..ac319ca4f7 100644
--- a/esphome/components/web_server_base/web_server_base.h
+++ b/esphome/components/web_server_base/web_server_base.h
@@ -130,8 +130,7 @@ class OTARequestHandler : public AsyncWebHandler {
   OTARequestHandler(WebServerBase *parent) : parent_(parent) {
 #if defined(USE_ESP_IDF) && defined(USE_WEBSERVER_OTA)
     this->ota_backend_ = nullptr;
-    this->ota_started_ = false;
-    this->ota_success_ = false;
+    this->ota_state_ = OTAState::IDLE;
 #endif
   }
   void handleRequest(AsyncWebServerRequest *request) override;
@@ -157,9 +156,17 @@ class OTARequestHandler : public AsyncWebHandler {
 
  private:
 #if defined(USE_ESP_IDF) && defined(USE_WEBSERVER_OTA)
+  // OTA state machine
+  enum class OTAState : uint8_t{
+      IDLE = 0,     // No OTA in progress
+      STARTED,      // OTA begin() succeeded
+      IN_PROGRESS,  // Writing data
+      SUCCESS,      // OTA end() succeeded
+      FAILED        // OTA failed at any stage
+  };
+
   void *ota_backend_{nullptr};
-  bool ota_started_{false};
-  bool ota_success_{false};
+  OTAState ota_state_{OTAState::IDLE};
 #endif
 };