The RTCDataChannel.onopen property is an event handler which specifies a function to be called when the open event is fired; this is a simple Event which is sent when the data channel's underlying data transport—the link over which the RTCDataChannel's messages flow—is established or re-established.


RTCDataChannel.onopen = function;


A function which the browser will call to handle the open event. The function receives as its only input parameter the event itself, of type Event.


This example adds a new data channel to an existing RTCPeerConnection, myPeerConnection. It then establishes an open event handler which updates some user interface elements to prepare them for being used to send messages over the data channel.

let dc = myPeerConnection.createDataChannel("Message Channel");

dc.onopen = function(event) {
  let messageBox = document.getElementById("messageBox");
  let sendButton = document.getElementById("sendButton");

  messageBox.disabled = false;
  sendButton.disabled = false;


WebRTC 1.0: Real-Time Communication Between Browsers (WebRTC 1.0)
# dom-rtcdatachannel-onopen

Browser compatibility

BCD tables only load in the browser

See also