Web/API/RTCDataChannel

The RTCDataChannel interface represents a network channel which can be used for bidirectional peer-to-peer transfers of arbitrary data. Every data channel is associated with an RTCPeerConnection, and each peer connection can have up to a theoretical maximum of 65,534 data channels (the actual limit may vary from browser to browser).

To create a data channel and ask a remote peer to join you, call the RTCPeerConnection's createDataChannel() method. The peer being invited to exchange data receives a datachannel event (which has type RTCDataChannelEvent) to let it know the data channel has been added to the connection.

Properties

Also inherits properties from: EventTarget

binaryType '

The property binaryType on the RTCDataChannel interface is a DOMString which specifies the type of JavaScript object which should be used to represent binary data received on the RTCDataChannel. Values allowed by the WebSocket.binaryType property are also permitted here: "blob" if Blob objects are being used or "arraybuffer" if ArrayBuffer objects are being used. The default is "blob".

bufferedAmount ' Read only

The read-only RTCDataChannel property bufferedAmount returns the number of bytes of data currently queued to be sent over the data channel.

bufferedAmountLowThreshold '

The RTCDataChannel property bufferedAmountLowThreshold is used to specify the number of bytes of buffered outgoing data that is considered "low." The default value is 0.

id ' Read only

The read-only RTCDataChannel property id returns an ID number (between 0 and 65,534) which uniquely identifies the RTCDataChannel.

label ' Read only

The read-only RTCDataChannel property label returns a DOMString containing a name describing the data channel. These labels are not required to be unique.

maxPacketLifeTime ' Read only

The read-only RTCDataChannel property maxPacketLifeTime returns the amount of time, in milliseconds, the browser is allowed to take to attempt to transmit a message, as set when the data channel was created, or null.

maxRetransmits ' Read only

The read-only RTCDataChannel property maxRetransmits returns the maximum number of times the browser should try to retransmit a message before giving up, as set when the data channel was created, or null, which indicates that there is no maximum.

negotiated Read only

The read-only RTCDataChannel property negotiated indicates whether the RTCDataChannel's connection was negotiated by the Web app (true) or by the WebRTC layer (false).

ordered ' Read only

The read-only RTCDataChannel property ordered indicates whether or not the data channel guarantees in-order delivery of messages; the default is true, which indicates that the data channel is indeed ordered.

protocol ' Read only

The read-only RTCDataChannel property protocol returns a DOMString containing the name of the subprotocol in use. If no protocol was specified when the data channel was created, then this property's value is "" (the empty string).

readyState ' Read only

The read-only RTCDataChannel property readyState returns an enum of type RTCDataChannelState which indicates the state of the data channel's underlying data connection.

reliable ' ' Read only

The read-only RTCDataChannel property reliable indicates whether or not the data channel is reliable.

stream ' ' Read only

The deprecated (and never part of the official specification) read-only RTCDataChannel property stream returns an ID number (between 0 and 65,535) which uniquely identifies the RTCDataChannel.

onbufferedamountlow '

The RTCDataChannel.onbufferedamountlow property is an EventHandler 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.

onclose '

The RTCDataChannel.onclose property is an EventHandler which specifies a function to be called by the browser when the close event is received by the RTCDataChannel. This is a simple Event which indicates that the data channel has closed down.

onclosing '

The RTCDataChannel.onclosing property is an EventHandler which specifies a function to be called by the browser when the closing event is received by the RTCDataChannel. This is a simple Event which indicates that the data channel is being closed, that is, RTCDataChannel transitions to "closing" state. For example, after RTCDataChannel.close() was called but the underlying data transport might not have been closed yet.

onerror '

The RTCDataChannel.onerror property is an EventHandler which specifies a function to be called when the error event is received. When an error occurs on the data channel, the function receives as input an ErrorEvent object describing the error which occurred.

onmessage '

The RTCDataChannel.onmessage property stores an EventHandler which specifies a function to be called when the message event is fired on the channel. This event is represented by the MessageEvent interface. This event is sent to the channel when a message is received from the other peer.

onopen '

The RTCDataChannel.onopen property is an EventHandler 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.

close()

The RTCDataChannel.close() method closes the RTCDataChannel. Either peer is permitted to call this method to initiate closure of the channel.

send()

The send() method of the RTCDataChannel interface sends data across the data channel to the remote peer.

Events

bufferedamountlow

Sent to the channel's onbufferedamountlow event handler when the number of bytes of data in the outgoing data buffer falls below the value specified by bufferedAmountLowThreshold.

close

Sent to the onclose event handler when the underlying data transport closes.

error

Sent to the onerror event handler when an error occurs on the data channel.

message

Sent to the onmessage event handler when a message has been received from the remote peer. The message contents can be found in the event's data property.

open

Sent to the onopen event handler when the data channel is first opened, or when an existing data channel's underlying connection re-opens.

Data format

The underlying data format is defined by the IEEE draft specification draft-ietf-mmusic-sctp-sdp. The current format specifies its protocol as either "UDP/DTLS/SCTP" (UDP carrying DTLS carrying SCTP) or "TCP/DTLS/SCTP" (TCP carrying DTLS carrying SCTP). Older browsers may only specify "DTLS/SCTP".

Example

var pc = new RTCPeerConnection();
var dc = pc.createDataChannel("my channel");

dc.onmessage = function (event) {
  console.log("received: " + event.data);
};

dc.onopen = function () {
  console.log("datachannel open");
};

dc.onclose = function () {
  console.log("datachannel close");
};

Specifications

Specification	Status	Comment
WebRTC 1.0: Real-time Communication Between BrowsersThe definition of 'RTCDataChannel' in that specification.	Candidate Recommendation	Initial specification.

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
RTCDataChannel Experimental'	Chrome Full support Yes	Edge Full support ≤79	Firefox Full support 24 Full support 24 No support 18 — 60 Alternate Name' Alternate Name' Uses the non-standard name: DataChannel	IE No support No	Opera Full support Yes	Safari Full support 11	WebView Android Full support 4.4	Chrome Android Full support 29	Firefox Android Full support 24 Full support 24 No support 18 — 60 Alternate Name' Alternate Name' Uses the non-standard name: DataChannel	Opera Android Full support Yes	Safari iOS Full support 11	Samsung Internet Android Full support 2.0
binaryType Experimental'	Chrome Full support Yes	Edge Full support ≤79	Firefox Full support 18	IE No support No	Opera Full support Yes	Safari Full support 11	WebView Android Full support 4.4	Chrome Android Full support 29	Firefox Android Full support 18	Opera Android Full support Yes	Safari iOS Full support 11	Samsung Internet Android Full support 2.0
bufferedAmount Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support 18	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support 18	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
bufferedamountlow event	Chrome Full support 57 Notes' Full support 57 Notes' Notes' The default for rtcpMuxPolicy is require.	Edge Full support ≤79 Notes' Full support ≤79 Notes' Notes' The default for rtcpMuxPolicy is require.	Firefox Full support Yes	IE No support No	Opera Full support 44 Notes' Full support 44 Notes' Notes' The default for rtcpMuxPolicy is require.	Safari Full support Yes	WebView Android Full support 57 Notes' Full support 57 Notes' Notes' The default for rtcpMuxPolicy is require.	Chrome Android Full support 57 Notes' Full support 57 Notes' Notes' The default for rtcpMuxPolicy is require.	Firefox Android Full support Yes	Opera Android Full support 43 Notes' Full support 43 Notes' Notes' The default for rtcpMuxPolicy is require.	Safari iOS No support No	Samsung Internet Android Full support 7.0 Notes' Full support 7.0 Notes' Notes' The default for rtcpMuxPolicy is require.
bufferedAmountLowThreshold Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android No support No	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
close	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
close event	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari ?	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS No support No	Samsung Internet Android Full support 6.0
error event	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari ?	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS No support No	Samsung Internet Android Full support 6.0
id Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox No support No	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android No support No	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
label Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
maxPacketLifeTime Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support 62	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support 62	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
maxRetransmits Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support 62	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support 62	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
message event	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support Yes	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support Yes	Samsung Internet Android Full support 6.0
negotiated Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support 68	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support 68	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
onbufferedamountlow Experimental'	Chrome Full support 57 Notes' Full support 57 Notes' Notes' The default for rtcpMuxPolicy is require.	Edge Full support ≤79 Notes' Full support ≤79 Notes' Notes' The default for rtcpMuxPolicy is require.	Firefox Full support Yes	IE No support No	Opera Full support 44 Notes' Full support 44 Notes' Notes' The default for rtcpMuxPolicy is require.	Safari Full support 11	WebView Android Full support 57 Notes' Full support 57 Notes' Notes' The default for rtcpMuxPolicy is require.	Chrome Android Full support 57 Notes' Full support 57 Notes' Notes' The default for rtcpMuxPolicy is require.	Firefox Android Full support Yes	Opera Android Full support 43 Notes' Full support 43 Notes' Notes' The default for rtcpMuxPolicy is require.	Safari iOS Full support 11	Samsung Internet Android Full support 7.0 Notes' Full support 7.0 Notes' Notes' The default for rtcpMuxPolicy is require.
onclose Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
onclosing Experimental'	Chrome Full support 81	Edge Full support 81	Firefox No support No	IE No support No	Opera Full support 68	Safari No support No	WebView Android Full support 81	Chrome Android Full support 81	Firefox Android No support No	Opera Android ?	Safari iOS No support No	Samsung Internet Android Full support 13.0
onerror Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox No support No	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android No support No	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
onmessage Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
onopen Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
open event	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support Yes	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support Yes	Samsung Internet Android Full support 6.0
ordered Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
priority	Chrome No support No	Edge No support No	Firefox ?	IE No support No	Opera ?	Safari No support No	WebView Android No support No	Chrome Android No support No	Firefox Android ?	Opera Android ?	Safari iOS No support No	Samsung Internet Android No support No
protocol Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
readyState Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
reliable Deprecated'	Chrome Full support 56	Edge Full support ≤79	Firefox No support No	IE No support No	Opera Full support 43	Safari No support No	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android No support No	Opera Android Full support 43	Safari iOS No support No	Samsung Internet Android Full support 6.0
Support for sctp-sdp-21 format	Chrome Full support 58	Edge Full support ≤79	Firefox Full support 63	IE No support No	Opera ?	Safari No support No	WebView Android Full support 58	Chrome Android Full support 58	Firefox Android Full support 63	Opera Android ?	Safari iOS No support No	Samsung Internet Android Full support 7.0
send	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support 11	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android Full support Yes	Opera Android Full support 43	Safari iOS Full support 11	Samsung Internet Android Full support 6.0
stream Deprecated'Non-standard'	Chrome Full support 56	Edge Full support ≤79	Firefox No support No	IE No support No	Opera Full support 43	Safari No support No	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android No support No	Opera Android Full support 43	Safari iOS No support No	Samsung Internet Android Full support 6.0

Legend

Full support  

Full support

No support  

No support

Compatibility unknown  

Compatibility unknown

Experimental. Expect behavior to change in the future.'

Experimental. Expect behavior to change in the future.

Non-standard. Expect poor cross-browser support.'

Non-standard. Expect poor cross-browser support.

Deprecated. Not for use in new websites.'

Deprecated. Not for use in new websites.

See implementation notes.'

See implementation notes.

Uses a non-standard name.'

Uses a non-standard name.

See also

• WebRTC API

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