The RTCDataChannel.onbufferedamountlow property is an event handler which specifies a function the browser calls when the bufferedamountlow event is sent to the RTCDataChannel. This event, which is represented by a simple Event object, is sent when the amount of data buffered to be sent falls to or below the threshold specified by the channel's bufferedAmountLowThreshold.

See Buffering in Using WebRTC data channels to learn more about how to work with the data channel buffer.


RTCDataChannel.onbufferedamountlow = function;


A function which the browser will call to handle the bufferedamountlow event. This function receives as its only input parameter a simple Event object representing the event which has occurred.


This example responds to the bufferedamountlow event by fetching up to 64kB of a file represented by an object source and calling RTCDataChannel.send() to queue up the retrieved data for sending on the data channel.

pc = new RTCPeerConnection();
dc = pc.createDataChannel("SendFile");

/* ... */

dc.onbufferedamountlow = function() {
  if (source.position <= source.length) {


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

Browser compatibility

BCD tables only load in the browser