File: class-websocket.md | Updated: 11/18/2025
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The WebSocket class represents WebSocket connections within a page. It provides the ability to inspect and manipulate the data being transmitted and received.
If you want to intercept or modify WebSocket frames, consider using WebSocketRoute .
Methods
Added before v1.9 webSocket.isClosed
Indicates that the web socket has been closed.
Usage
WebSocket.isClosed();
Returns
Added before v1.9 webSocket.url
Contains the URL of the WebSocket.
Usage
WebSocket.url();
Returns
Added in: v1.10 webSocket.waitForFrameReceived
Performs action and waits for a frame to be sent. If predicate is provided, it passes WebSocketFrame
value into the predicate function and waits for predicate(webSocketFrame) to return a truthy value. Will throw an error if the WebSocket or Page is closed before the frame is received.
Usage
WebSocket.waitForFrameReceived(callback);WebSocket.waitForFrameReceived(callback, options);
Arguments
options WebSocket.WaitForFrameReceivedOptions (optional)
setPredicate Predicate
<WebSocketFrame
> (optional) Added in: v1.9#
Receives the WebSocketFrame object and resolves to truthy value when the waiting should resolve.
setTimeout double
(optional) Added in: v1.9#
Maximum time to wait for in milliseconds. Defaults to 30000 (30 seconds). Pass 0 to disable timeout. The default value can be changed by using the BrowserContext.setDefaultTimeout()
.
callback Runnable
Added in: v1.9#
Callback that performs the action triggering the event.
Returns
Added in: v1.10 webSocket.waitForFrameSent
Performs action and waits for a frame to be sent. If predicate is provided, it passes WebSocketFrame
value into the predicate function and waits for predicate(webSocketFrame) to return a truthy value. Will throw an error if the WebSocket or Page is closed before the frame is sent.
Usage
WebSocket.waitForFrameSent(callback);WebSocket.waitForFrameSent(callback, options);
Arguments
options WebSocket.WaitForFrameSentOptions (optional)
setPredicate Predicate
<WebSocketFrame
> (optional) Added in: v1.9#
Receives the WebSocketFrame object and resolves to truthy value when the waiting should resolve.
setTimeout double
(optional) Added in: v1.9#
Maximum time to wait for in milliseconds. Defaults to 30000 (30 seconds). Pass 0 to disable timeout. The default value can be changed by using the BrowserContext.setDefaultTimeout()
.
callback Runnable
Added in: v1.9#
Callback that performs the action triggering the event.
Returns
Events
Added before v1.9 webSocket.onClose(handler)
Fired when the websocket closes.
Usage
WebSocket.onClose(handler)
Event data
Added in: v1.9 webSocket.onFrameReceived(handler)
Fired when the websocket receives a frame.
Usage
WebSocket.onFrameReceived(handler)
Event data
Added in: v1.9 webSocket.onFrameSent(handler)
Fired when the websocket sends a frame.
Usage
WebSocket.onFrameSent(handler)
Event data
Added in: v1.9 webSocket.onSocketError(handler)
Fired when the websocket has an error.
Usage
WebSocket.onSocketError(handler)
Event data