dom / latest / websocket / message_event.html /

WebSocket: message event

The message event is fired when data is received through a WebSocket.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener('message', event => { })

onmessage = event => { }

Event type

Event properties

In addition to the properties listed below, properties from the parent interface, Event, are available.

data Read only

The data sent by the message emitter.

origin Read only

A USVString representing the origin of the message emitter.

lastEventId Read only

A DOMString representing a unique ID for the event.

source Read only

A MessageEventSource (which can be a Window, MessagePort, or ServiceWorker object) representing the message emitter.

ports Read only

An array of MessagePort objects representing the ports associated with the channel the message is being sent through (where appropriate, e.g. in channel messaging or when sending a message to a shared worker).

Examples

// Create WebSocket connection.
const socket = new WebSocket('ws://localhost:8080');

// Listen for messages
socket.addEventListener('message', function (event) {
    console.log('Message from server ', event.data);
});

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
message_event
4
12
7
10
12.1
5
≤37
18
7
12.1
4.2
1.0

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/WebSocket/message_event