CloseEvent

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.

See full compatibility

Note: This feature is available in Web Workers.

A CloseEvent is sent to clients using WebSockets when the connection is closed. This is delivered to the listener indicated by the WebSocket object's onclose attribute.

Constructor

CloseEvent(): Creates a new CloseEvent.

Instance properties

This interface also inherits properties from its parent, Event.

CloseEvent.code Read only: Returns an unsigned short containing the close code.
CloseEvent.reason Read only: Returns a string indicating the reason the server closed the connection. This is specific to the particular server and sub-protocol.
CloseEvent.wasClean Read only: Returns a boolean value that Indicates whether or not the connection was cleanly closed.

Instance methods

This interface also inherits methods from its parent, Event.

Specifications

Specification
WebSockets # the-closeevent-interface

Browser compatibility

	desktop					mobile							server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`CloseEvent`	Chrome – Full support Chrome 15 (Release date: 2011-10-25) footnote Full support	Edge – Full support Edge 12 (Release date: 2015-07-29) footnote Full support	Firefox – Full support Firefox 8 (Release date: 2011-11-08) footnote footnote Before Firefox 12, the close code `CLOSE_NORMAL` was used when the channel was closed due to an unexpected error or unspecified error condition. footnote Before Firefox 8, the `WebSocket` close event was sent to the listener as a simple event.	Opera – Full support Opera 12.1 (Release date: 2012-11-20) footnote Full support	Safari – Full support Safari 6 (Release date: 2012-07-25) footnote Full support	Chrome Android – Full support Chrome Android 18 (Release date: 2012-06-27) footnote Full support	Firefox for Android – Full support Firefox for Android 8 (Release date: 2011-11-08) footnote Full support	Opera Android – Full support Opera Android 12.1 (Release date: 2012-10-09) footnote Full support	Safari on iOS – Full support Safari on iOS 6 (Release date: 2012-09-10) footnote Full support	Samsung Internet – Full support Samsung Internet 1 (Release date: 2013-04-27) footnote Full support	WebView Android – Full support WebView Android 4.4 (Release date: 2013-12-09) footnote Full support	WebView on iOS – Full support WebView on iOS 6 (Release date: 2012-09-10) footnote Full support	Bun – Full support Bun 1 (Release date: 2023-09-08) footnote Full support	Deno – Full support Deno 1.4 (Release date: 2020-09-13) footnote Full support	Node.js – Full support Node.js 23 (Release date: 2024-10-16) footnote Full support
`CloseEvent()` constructor	Chrome – Full support Chrome 16 (Release date: 2011-12-13) footnote Full support	Edge – Full support Edge 14 (Release date: 2016-08-02) footnote Full support	Firefox – Full support Firefox 11 (Release date: 2012-03-13) footnote Full support	Opera – Full support Opera 12.1 (Release date: 2012-11-20) footnote Full support	Safari – Full support Safari 6 (Release date: 2012-07-25) footnote Full support	Chrome Android – Full support Chrome Android 18 (Release date: 2012-06-27) footnote Full support	Firefox for Android – Full support Firefox for Android 14 (Release date: 2012-06-26) footnote Full support	Opera Android – Full support Opera Android 12.1 (Release date: 2012-10-09) footnote Full support	Safari on iOS – Full support Safari on iOS 6 (Release date: 2012-09-10) footnote Full support	Samsung Internet – Full support Samsung Internet 1 (Release date: 2013-04-27) footnote Full support	WebView Android – Full support WebView Android 4.4 (Release date: 2013-12-09) footnote Full support	WebView on iOS – Full support WebView on iOS 6 (Release date: 2012-09-10) footnote Full support	Bun – Full support Bun 1 (Release date: 2023-09-08) footnote Full support	Deno – Full support Deno 1.4 (Release date: 2020-09-13) footnote Full support	Node.js – Full support Node.js 23 (Release date: 2024-10-16) footnote Full support
`code`	Chrome – Full support Chrome 15 (Release date: 2011-10-25) footnote Full support	Edge – Full support Edge 12 (Release date: 2015-07-29) footnote Full support	Firefox – Full support Firefox 8 (Release date: 2011-11-08) footnote Full support	Opera – Full support Opera 12.1 (Release date: 2012-11-20) footnote Full support	Safari – Full support Safari 6 (Release date: 2012-07-25) footnote Full support	Chrome Android – Full support Chrome Android 18 (Release date: 2012-06-27) footnote Full support	Firefox for Android – Full support Firefox for Android 8 (Release date: 2011-11-08) footnote Full support	Opera Android – Full support Opera Android 12.1 (Release date: 2012-10-09) footnote Full support	Safari on iOS – Full support Safari on iOS 6 (Release date: 2012-09-10) footnote Full support	Samsung Internet – Full support Samsung Internet 1 (Release date: 2013-04-27) footnote Full support	WebView Android – Full support WebView Android 4.4 (Release date: 2013-12-09) footnote Full support	WebView on iOS – Full support WebView on iOS 6 (Release date: 2012-09-10) footnote Full support	Bun – Full support Bun 1 (Release date: 2023-09-08) footnote Full support	Deno – Full support Deno 1.4 (Release date: 2020-09-13) footnote Full support	Node.js – Full support Node.js 23 (Release date: 2024-10-16) footnote Full support
`reason`	Chrome – Full support Chrome 15 (Release date: 2011-10-25) footnote Full support	Edge – Full support Edge 12 (Release date: 2015-07-29) footnote Full support	Firefox – Full support Firefox 8 (Release date: 2011-11-08) footnote Full support	Opera – Full support Opera 12.1 (Release date: 2012-11-20) footnote Full support	Safari – Full support Safari 6 (Release date: 2012-07-25) footnote Full support	Chrome Android – Full support Chrome Android 18 (Release date: 2012-06-27) footnote Full support	Firefox for Android – Full support Firefox for Android 8 (Release date: 2011-11-08) footnote Full support	Opera Android – Full support Opera Android 12.1 (Release date: 2012-10-09) footnote Full support	Safari on iOS – Full support Safari on iOS 6 (Release date: 2012-09-10) footnote Full support	Samsung Internet – Full support Samsung Internet 1 (Release date: 2013-04-27) footnote Full support	WebView Android – Full support WebView Android 4.4 (Release date: 2013-12-09) footnote Full support	WebView on iOS – Full support WebView on iOS 6 (Release date: 2012-09-10) footnote Full support	Bun – Full support Bun 1 (Release date: 2023-09-08) footnote Full support	Deno – Full support Deno 1.4 (Release date: 2020-09-13) footnote Full support	Node.js – Full support Node.js 23 (Release date: 2024-10-16) footnote Full support
`wasClean`	Chrome – Full support Chrome 15 (Release date: 2011-10-25) footnote Full support	Edge – Full support Edge 12 (Release date: 2015-07-29) footnote Full support	Firefox – Full support Firefox 8 (Release date: 2011-11-08) footnote Full support	Opera – Full support Opera 12.1 (Release date: 2012-11-20) footnote Full support	Safari – Full support Safari 6 (Release date: 2012-07-25) footnote Full support	Chrome Android – Full support Chrome Android 18 (Release date: 2012-06-27) footnote Full support	Firefox for Android – Full support Firefox for Android 8 (Release date: 2011-11-08) footnote Full support	Opera Android – Full support Opera Android 12.1 (Release date: 2012-10-09) footnote Full support	Safari on iOS – Full support Safari on iOS 6 (Release date: 2012-09-10) footnote Full support	Samsung Internet – Full support Samsung Internet 1 (Release date: 2013-04-27) footnote Full support	WebView Android – Full support WebView Android 4.4 (Release date: 2013-12-09) footnote Full support	WebView on iOS – Full support WebView on iOS 6 (Release date: 2012-09-10) footnote Full support	Bun – Full support Bun 1 (Release date: 2023-09-08) footnote Full support	Deno – Full support Deno 1.4 (Release date: 2020-09-13) footnote Full support	Node.js – Full support Node.js 23 (Release date: 2024-10-16) footnote Full support

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

Full support: Full support
: See implementation notes.

See also

WebSocket

This page was last modified on Sep 25, 2024 by MDN contributors.

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