WebSocket: message event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Note: This feature is available in Web Workers.

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.

js
addEventListener("message", (event) => { })

onmessage = (event) => { }

Event type

A MessageEvent. Inherits from Event.

Event MessageEvent

Examples

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

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

Specifications

Specification
WebSockets
# dom-websocket-onmessage

Browser compatibility

See also