diff --git a/backend/open_webui/models/chat_messages.py b/backend/open_webui/models/chat_messages.py
index b33be1f7eb..cc160997ef 100644
--- a/backend/open_webui/models/chat_messages.py
+++ b/backend/open_webui/models/chat_messages.py
@@ -394,6 +394,24 @@ class ChatMessageTable:
             await db.commit()
             return True
 
+    async def delete_message_ids_by_chat_id(
+        self,
+        chat_id: str,
+        message_ids: set[str],
+        db: Optional[AsyncSession] = None,
+    ) -> bool:
+        """Delete specific ``chat_message`` rows by their original message IDs."""
+        if not message_ids:
+            return True
+        async with get_async_db_context(db) as db:
+            await db.execute(
+                delete(ChatMessage)
+                .where(ChatMessage.chat_id == chat_id)
+                .where(ChatMessage.id.in_({f'{chat_id}-{mid}' for mid in message_ids}))
+            )
+            await db.commit()
+            return True
+
     # Analytics methods
     async def get_message_count_by_model(
         self,
diff --git a/backend/open_webui/models/chats.py b/backend/open_webui/models/chats.py
index 954d8640f0..a19cdf1a6b 100644
--- a/backend/open_webui/models/chats.py
+++ b/backend/open_webui/models/chats.py
@@ -394,6 +394,9 @@ class ChatTable:
         try:
             async with get_async_db_context(db) as db:
                 chat_item = await db.get(Chat, id)
+                if chat_item is None:
+                    return None
+
                 chat_item.chat = self._clean_null_bytes(chat)
                 chat_item.title = self._clean_null_bytes(chat['title']) if 'title' in chat else 'New Chat'
 
@@ -495,6 +498,26 @@ class ChatTable:
             except Exception as e:
                 log.warning('Backfill failed for message %s in chat %s: %s', message_id, chat_id, e)
 
+    async def reconcile_messages_by_chat_id(
+        self, chat_id: str, user_id: str, messages: dict[str, dict]
+    ) -> None:
+        """Sync ``chat_message`` rows with the committed JSON blob.
+
+        Upserts current messages via ``backfill_messages_by_chat_id``
+        and deletes orphaned rows whose message_id no longer appears
+        in the blob.  Best-effort: errors are logged but never raised.
+        """
+        try:
+            await self.backfill_messages_by_chat_id(chat_id, user_id, messages)
+
+            existing_map = await ChatMessages.get_messages_map_by_chat_id(chat_id)
+            if existing_map is not None:
+                orphaned_ids = set(existing_map.keys()) - set(messages.keys())
+                if orphaned_ids:
+                    await ChatMessages.delete_message_ids_by_chat_id(chat_id, orphaned_ids)
+        except Exception as e:
+            log.warning('Failed to reconcile chat_message rows for chat %s: %s', chat_id, e)
+
     async def get_messages_map_by_chat_id(self, id: str) -> dict | None:
         """Message map for walking history (see ``get_message_list``).
 
diff --git a/backend/open_webui/routers/chats.py b/backend/open_webui/routers/chats.py
index 9344173807..7c6f3dea9d 100644
--- a/backend/open_webui/routers/chats.py
+++ b/backend/open_webui/routers/chats.py
@@ -987,6 +987,14 @@ async def update_chat_by_id(
                 msg['content'] = serialize_output(msg['output'])
 
         chat = await Chats.update_chat_by_id(id, updated_chat, db=db)
+
+        # Reconcile chat_message rows with the committed blob.
+        # This is the only caller where the frontend pushes a full
+        # history with potential edits, deletions, or new branches.
+        messages = (updated_chat.get('history') or {}).get('messages') or {}
+        if messages:
+            await Chats.reconcile_messages_by_chat_id(id, user.id, messages)
+
         return ChatResponse(**chat.model_dump())
     else:
         raise HTTPException(