WebSocket: close event
The close event is fired when a connection with a WebSocket is closed.
Syntax

Use the event name in methods like addEventListener(), or set an event handler property. addEventListener('close', event => { })

onclose = event => { }


Event type

An CloseEvent. Inherits from Event.
   Event     CloseEvent  

Event properties

In addition to the properties listed below, properties from the parent interface, Event, are available.  
codeRead only 
  Returns an unsigned short containing the close code sent by the server.  
reasonRead only 
  Returns a DOMString indicating the reason the server closed the connection. This is specific to the particular server and sub-protocol.  
wasCleanRead only 
  Returns a boolean value that Indicates whether or not the connection was cleanly closed.  

Examples

You might want to know when the connection has been closed so that you can update the UI or, perhaps, save data about the closed connection. Given that you have a variable called exampleSocket that refers to an opened WebSocket, this handler would handle the situation where the socket has been closed. exampleSocket.addEventListener('close', (event) => {
  console.log('The connection has been closed successfully.');
});
 You can perform the same actions using the event handler property, like this: exampleSocket.onclose = function (event) {
  console.log('The connection has been closed successfully.');
};


Specifications

Specification
WebSockets Standard # dom-websocket-onclose

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



close_event
4
12
7
10
12.1
5
≤37
18
7
12.1
4.2
1.0


See also
 WebSocket: error event WebSocket: message event WebSocket: open event Writing WebSocket client applications 


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Last modified: Jan 13, 2022, by MDN contributors


    
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