Web/API/WebSocket/onopen

The WebSocket.onopen property is an EventHandler that is called when the WebSocket connection's readyState changes to 1; this indicates that the connection is ready to send and receive data. It is called with an Event.

Syntax

aWebSocket.onopen = function(event) {
  console.log("WebSocket is open now.");
};

Value

An EventListener.

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of 'WebSocket: onopen' in that specification.	Living Standard	Initial definition

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
onopen	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE ?	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes

Legend

Full support  

Full support

Compatibility unknown  

Compatibility unknown

WebSocket.onopen by Mozilla Contributors is licensed under CC-BY-SA 2.5.