SeleniumHQ/selenium · error · WebDriverException

Timed out waiting for response to BiDi command {current_id}

Error message

Timed out waiting for response to BiDi command {current_id}

What it means

Raised after `_wait_until(lambda: current_id in self._messages)` elapses without the BiDi response (or error) for a command id arriving. The connection successfully sent the command over the websocket, but no matching response landed in `self._messages` within `response_wait_timeout`.

Source

Thrown at py/selenium/webdriver/remote/websocket_connection.py:133

        self._started = False
        self._ws = None

    def execute(self, command):
        with self._id_lock:
            self._id += 1
            current_id = self._id
        payload = self._serialize_command(command)
        payload["id"] = current_id
        if self.session_id:
            payload["sessionId"] = self.session_id

        data = json.dumps(payload, cls=_BiDiEncoder)
        logger.debug(f"-> {data}"[: self._max_log_message_size])
        self._ws.send(data)

        self._wait_until(lambda: current_id in self._messages)
        if current_id not in self._messages:
            raise WebDriverException(f"Timed out waiting for response to BiDi command {current_id}")
        response = self._messages.pop(current_id)

        if "error" in response:
            error = response["error"]
            if "message" in response:
                error_msg = f"{error}: {response['message']}"
                raise WebDriverException(error_msg)
            else:
                raise WebDriverException(error)
        else:
            result = response["result"]
            return self._deserialize_result(result, command)

    def add_callback(self, event, callback):
        event_name = event.event_class
        if event_name not in self.callbacks:
            self.callbacks[event_name] = []

View on GitHub (pinned to aa36b38e69)

Solutions

1. Increase the `timeout` (response_wait_timeout) passed to WebSocketConnection.
2. Confirm the websocket is still open (watch on_error/on_close) before retrying.
3. Retry the BiDi command with backoff; recreate the session if the connection was reset.
4. Check the browser/driver logs for the unhandled command id.

Example fix

# before
conn = WebSocketConnection(url, timeout=5, interval=0.1)

# after
conn = WebSocketConnection(url, timeout=30, interval=0.1)

try:
    result = conn.execute(cmd)
except WebDriverException as e:
    if "Timed out waiting for response to BiDi command" in str(e):
        # optional: verify socket liveness, then retry once with backoff
        result = retry_bidi(conn, cmd)
    else:
        raise

When it happens

Trigger: Calling any BiDi command (e.g. browsingContext.navigate, script.callFunction) when the remote end hangs, the websocket silently dropped, a slow operation exceeds response_wait_timeout, or the response arrived but was routed under a different id.

Common situations: Network instability or proxy throttling, a remote BiDi implementation that stalls, a timeout set too low for heavy pages, or a navigation/reset that tears down the BiDi session mid-command.

Understand the failure class

• Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

• Pattern must be an instance of UrlPattern. Received: '${patt
• Pattern must be an instance of UrlPattern. Received:'${patte
• Pattern must be an instance of String. Received:'${pattern}'
• BiDi connection is closed
• BiDi connection is not open

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/49c1eb8b6f8bd814. Report an issue: GitHub.