RTCDataChannel: open event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

The WebRTC open event is sent to an RTCDataChannel object's onopen event handler when the underlying transport used to send and receive the data channel's messages is opened or reopened.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

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

onopen = (event) => { }

Event type

An RTCDataChannelEvent. Inherits from Event.

Event RTCDataChannelEvent

Event properties

Also inherits properties from its parent interface, Event.

channel Read only

Returns the RTCDataChannel associated with the event.

Examples

This example adds to the RTCDataChannel dc a handler for the open event that adjusts the user interface to indicate that a chat window is ready to be used after a connection has been established. It enables the message input box and send button as well as enabling the disconnect button and disabling the connect button. Finally, the message input box is focused so the user can immediately begin to type.

js
dc.addEventListener("open", (ev) => {
  messageInputBox.disabled = false;
  sendMessageButton.disabled = false;
  disconnectButton.disabled = false;
  connectButton.disabled = true;

  messageInputBox.focus();
});

This can also be done by directly setting the value of the channel's onopen event handler property.

js
dc.onopen = (ev) => {
  messageInputBox.disabled = false;
  sendMessageButton.disabled = false;
  disconnectButton.disabled = false;
  connectButton.disabled = true;

  messageInputBox.focus();
};

Specifications

Specification
WebRTC: Real-Time Communication in Browsers
# event-datachannel-open
WebRTC: Real-Time Communication in Browsers
# dom-rtcdatachannel-onopen

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
open event
Chrome – Full support
Chrome 24 (Release date: 2013-01-10)
footnote Full support
Edge – Full support
Edge 79 (Release date: 2020-01-15)
footnote Full support
Firefox – Full support
Firefox 22 (Release date: 2013-06-25)
footnote Full support
Opera – Full support
Opera 15 (Release date: 2013-07-02)
footnote Full support
Safari – Full support
Safari 11 (Release date: 2017-09-19)
footnote Full support
Chrome Android – Full support
Chrome Android 25 (Release date: 2013-02-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 24 (Release date: 2013-09-17)
footnote Full support
Opera Android – Full support
Opera Android 14 (Release date: 2013-05-21)
footnote Full support
Safari on iOS – Full support
Safari on iOS 11 (Release date: 2017-09-19)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1.5 (Release date: 2013-09-25)
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 11 (Release date: 2017-09-19)
footnote Full support

Legend

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

Full support
Full support

See also