CloseEvent: reason property

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 reason read-only property of the CloseEvent interface returns the WebSocket connection close reason the server gave for closing the connection; that is, a concise human-readable prose explanation for the closure.

Value

A string.

Examples

The following example prints the value of reason to the console.

js
WebSocket.onclose = (event) => {
  console.log(event.reason);
};

Specifications

Specification
WebSockets
# ref-for-dom-closeevent-reason②

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
reason

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also

  • RFC 6455 (the WebSocket Protocol specification)