diff --git a/backend/open_webui/socket/main.py b/backend/open_webui/socket/main.py
index cb01d62e00..25792b0e78 100644
--- a/backend/open_webui/socket/main.py
+++ b/backend/open_webui/socket/main.py
@@ -57,6 +57,29 @@ REDIS = None
 # Configure CORS for Socket.IO
 SOCKETIO_CORS_ORIGINS = '*' if CORS_ALLOW_ORIGIN == ['*'] else CORS_ALLOW_ORIGIN
 
+class LocalFilteredRedisManager(socketio.AsyncRedisManager):
+    """AsyncRedisManager that drops pub/sub emits with no local recipients.
+
+    Every instance subscribed to the shared Socket.IO channel receives every
+    emit published by the whole fleet. Upstream ``_handle_emit`` re-encodes
+    the full packet before discovering the target room has no participants on
+    this instance, so each instance burns CPU serializing payloads addressed
+    to sessions it does not host — a cost that grows with instance count.
+    Bail out before that work when the room is empty here. Only string
+    rooms take the fast path; broadcasts (``room=None``) and any other
+    room shape (e.g. lists, which upstream indexes before validating)
+    always pass through unchanged.
+    """
+
+    async def _handle_emit(self, message):
+        room = message.get('room')
+        if isinstance(room, str):
+            namespace = message.get('namespace') or '/'
+            if next(self.get_participants(namespace, room), None) is None:
+                return
+        await super()._handle_emit(message)
+
+
 if WEBSOCKET_MANAGER == 'redis':
     sentinel_hosts = WEBSOCKET_SENTINEL_HOSTS or ''
     ws_redis_url = (
@@ -64,7 +87,7 @@ if WEBSOCKET_MANAGER == 'redis':
         if sentinel_hosts
         else WEBSOCKET_REDIS_URL
     )
-    redis_manager = socketio.AsyncRedisManager(ws_redis_url, redis_options=WEBSOCKET_REDIS_OPTIONS)
+    redis_manager = LocalFilteredRedisManager(ws_redis_url, redis_options=WEBSOCKET_REDIS_OPTIONS)
     sio = socketio.AsyncServer(
         cors_allowed_origins=SOCKETIO_CORS_ORIGINS,
         async_mode='asgi',
diff --git a/backend/requirements-min.txt b/backend/requirements-min.txt
index d5646443e6..7ccc3f7261 100644
--- a/backend/requirements-min.txt
+++ b/backend/requirements-min.txt
@@ -33,6 +33,7 @@ alembic==1.18.4
 
 pycrdt==0.13.1
 redis
+hiredis
 
 APScheduler==3.11.2
 RestrictedPython==8.2
diff --git a/backend/requirements.txt b/backend/requirements.txt
index e33bf131ea..4a3169762f 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -30,7 +30,8 @@ psycopg[binary]==3.3.4
 alembic==1.18.4
 
 pycrdt==0.13.1
-redis==8.0.0
+redis==8.0.1
+hiredis==3.4.0
 
 APScheduler==3.11.2
 RestrictedPython==8.2
diff --git a/pyproject.toml b/pyproject.toml
index 74659791df..1944904e53 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,7 +38,8 @@ dependencies = [
     "alembic==1.18.4",
 
     "pycrdt==0.13.1",
-    "redis==8.0.0",
+    "redis==8.0.1",
+    "hiredis==3.4.0",
     # "valkey-glide-sync==2.3.1",  # optional: install manually if VECTOR_DB=valkey
 
     "pytz==2026.2",