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 theRTCDataChannel
interface is aDOMString
which specifies the type of JavaScript object which should be used to represent binary data received on theRTCDataChannel
. Values allowed by theWebSocket.binaryType
property are also permitted here:"blob"
ifBlob
objects are being used or"arraybuffer"
ifArrayBuffer
objects are being used. The default is"blob"
. bufferedAmount
Read only- The read-only
RTCDataChannel
propertybufferedAmount
returns the number of bytes of data currently queued to be sent over the data channel. bufferedAmountLowThreshold
- The
RTCDataChannel
propertybufferedAmountLowThreshold
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
propertyid
returns an ID number (between 0 and 65,534) which uniquely identifies theRTCDataChannel
. label
Read only- The read-only
RTCDataChannel
propertylabel
returns aDOMString
containing a name describing the data channel. These labels are not required to be unique. maxPacketLifeTime
Read only- The read-only
RTCDataChannel
propertymaxPacketLifeTime
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, ornull
. maxRetransmits
Read only- The read-only
RTCDataChannel
propertymaxRetransmits
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, ornull
, which indicates that there is no maximum. negotiated
Read only- The read-only
RTCDataChannel
propertynegotiated
indicates whether theRTCDataChannel
's connection was negotiated by the Web app (true
) or by the WebRTC layer (false
). ordered
Read only- The read-only
RTCDataChannel
propertyordered
indicates whether or not the data channel guarantees in-order delivery of messages; the default istrue
, which indicates that the data channel is indeed ordered. protocol
Read only- The read-only
RTCDataChannel
propertyprotocol
returns aDOMString
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
propertyreadyState
returns an enum of typeRTCDataChannelState
which indicates the state of the data channel's underlying data connection. Read onlyreliable
- The read-only
RTCDataChannel
propertyreliable
indicates whether or not the data channel is reliable. Read onlystream
- The deprecated (and never part of the official specification) read-only
RTCDataChannel
propertystream
returns an ID number (between 0 and 65,535) which uniquely identifies theRTCDataChannel
. onbufferedamountlow
- The
RTCDataChannel.onbufferedamountlow
property is anEventHandler
which specifies a function the browser calls when thebufferedamountlow
event is sent to theRTCDataChannel
. This event, which is represented by a simpleEvent
object, is sent when the amount of data buffered to be sent falls to or below the threshold specified by the channel'sbufferedAmountLowThreshold
. onclose
- The
RTCDataChannel.onclose
property is anEventHandler
which specifies a function to be called by the browser when theclose
event is received by theRTCDataChannel
. This is a simpleEvent
which indicates that the data channel has closed down. onclosing
- The
RTCDataChannel.onclosing
property is anEventHandler
which specifies a function to be called by the browser when theclosing
event is received by theRTCDataChannel
. This is a simpleEvent
which indicates that the data channel is being closed, that is,RTCDataChannel
transitions to "closing" state. For example, afterRTCDataChannel.close()
was called but the underlying data transport might not have been closed yet. onerror
- The
RTCDataChannel.onerror
property is anEventHandler
which specifies a function to be called when theerror
event is received. When an error occurs on the data channel, the function receives as input anErrorEvent
object describing the error which occurred. onmessage
- The
RTCDataChannel.onmessage
property stores anEventHandler
which specifies a function to be called when themessage
event is fired on the channel. This event is represented by theMessageEvent
interface. This event is sent to the channel when a message is received from the other peer. onopen
- The
RTCDataChannel.onopen
property is anEventHandler
which specifies a function to be called when theopen
event is fired; this is a simpleEvent
which is sent when the data channel's underlying data transport—the link over which theRTCDataChannel
's messages flow—is established or re-established. close()
- The
RTCDataChannel.close()
method closes theRTCDataChannel
. Either peer is permitted to call this method to initiate closure of the channel. send()
- The
send()
method of theRTCDataChannel
interface sends data across the data channel to the remote peer.
Event handlers
Also inherits event handlers from: EventTarget
Methods
Also inherits methods from: EventTarget
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 bybufferedAmountLowThreshold
. 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'sdata
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 Browsers The definition of 'RTCDataChannel' in that specification. |
Candidate Recommendation | Initial specification. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
RTCDataChannel | Chrome Full support Yes | Edge Full support ≤79 | Firefox
Full support
24
| IE No support No | Opera Full support Yes | Safari Full support Yes | WebView Android Full support 4.4 | Chrome Android Full support 29 | Firefox Android
Full support
24
| Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support 2.0 |
binaryType | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 18 | IE No support No | Opera Full support Yes | Safari Full support Yes | WebView Android Full support 4.4 | Chrome Android Full support 29 | Firefox Android Full support 18 | Opera Android Full support Yes | Safari iOS No support No | Samsung Internet Android Full support 2.0 |
bufferedAmount | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support 18 | 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 18 | Opera Android Full support 43 | Safari iOS No support No | Samsung Internet Android Full support 6.0 |
bufferedamountlow event | Chrome
Full support
57
| Edge
Full support
≤79
| Firefox Full support Yes | IE No support No | Opera
Full support
44
| Safari Full support Yes | WebView Android
Full support
57
| Chrome Android
Full support
57
| Firefox Android Full support Yes | Opera Android
Full support
43
| Safari iOS No support No | Samsung Internet Android
Full support
7.0
|
bufferedAmountLowThreshold | 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 No support No | Opera Android Full support 43 | Safari iOS No support No | 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 No support No | 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 |
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 | 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 |
label | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support Yes | IE No support No | Opera Full support 43 | Safari No support No | 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 |
maxPacketLifeTime | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support 62 | IE No support No | Opera Full support 43 | Safari No support No | WebView Android Full support 56 | Chrome Android Full support 56 | Firefox Android Full support 62 | Opera Android Full support 43 | Safari iOS No support No | Samsung Internet Android Full support 6.0 |
maxRetransmits | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support 62 | IE No support No | Opera Full support 43 | Safari No support No | WebView Android Full support 56 | Chrome Android Full support 56 | Firefox Android Full support 62 | Opera Android Full support 43 | Safari iOS No support No | 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 | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support 68 | IE No support No | Opera Full support 43 | Safari No support No | WebView Android Full support 56 | Chrome Android Full support 56 | Firefox Android Full support 68 | Opera Android Full support 43 | Safari iOS No support No | Samsung Internet Android Full support 6.0 |
onbufferedamountlow | Chrome
Full support
57
| Edge
Full support
≤79
| Firefox Full support Yes | IE No support No | Opera
Full support
44
| Safari Full support Yes | WebView Android
Full support
57
| Chrome Android
Full support
57
| Firefox Android Full support Yes | Opera Android
Full support
43
| Safari iOS No support No | Samsung Internet Android
Full support
7.0
|
onclose | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support Yes | IE No support No | Opera Full support 43 | Safari No support No | 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 |
onclosing | 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 ? |
onerror | 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 |
onmessage | 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 |
onopen | 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 |
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 | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support Yes | IE No support No | Opera Full support 43 | Safari No support No | 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 |
priority | Chrome No support No | Edge No support No | Firefox ? | IE No support No | Opera ? | Safari ? | 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 | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support Yes | IE No support No | Opera Full support 43 | Safari No support No | 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 |
readyState | Chrome Full support 56 | Edge Full support ≤79 | Firefox Full support Yes | IE No support No | Opera Full support 43 | Safari No support No | 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 |
reliable | 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 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 |
stream | 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.