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RTCPeerConnection

The RTCPeerConnection interface represents a WebRTC connection between the local computer and a remote peer. It provides methods to connect to a remote peer, maintain and monitor the connection, and close the connection once it's no longer needed.

EventTarget RTCPeerConnection

Constructor

RTCPeerConnection()

Returns a new RTCPeerConnection, representing a connection between the local device and a remote peer.

Instance properties

Also inherits properties from EventTarget.

canTrickleIceCandidates Read only

Returns a boolean value which indicates whether or not the remote peer can accept trickled ICE candidates.

connectionState Read only

Indicates the current state of the peer connection by returning one of the strings: new, connecting, connected, disconnected, failed, or closed.

currentLocalDescription Read only

Returns an RTCSessionDescription object describing the local end of the connection as it was most recently successfully negotiated since the last time this RTCPeerConnection finished negotiating and connecting to a remote peer. Also included is a list of any ICE candidates that may already have been generated by the ICE agent since the offer or answer represented by the description was first instantiated.

currentRemoteDescription Read only

Returns an RTCSessionDescription object describing the remote end of the connection as it was most recently successfully negotiated since the last time this RTCPeerConnection finished negotiating and connecting to a remote peer. Also included is a list of any ICE candidates that may already have been generated by the ICE agent since the offer or answer represented by the description was first instantiated.

iceConnectionState Read only

Returns a string which state of the ICE agent associated with this RTCPeerConnection. It can be one of the following values: new, checking, connected, completed, failed, disconnected, or closed.

iceGatheringState Read only

Returns a string that describes connection's ICE gathering state. This lets you detect, for example, when collection of ICE candidates has finished. Possible values are: new, gathering, or complete.

localDescription Read only

Returns an RTCSessionDescription describing the session for the local end of the connection. If it has not yet been set, returns null.

peerIdentity Read only

Returns a Promise that resolves to an RTCIdentityAssertion which contains a string identifying the remote peer. Once this promise resolves successfully, the resulting identity is the target peer identity and will not change for the duration of the connection.

pendingLocalDescription Read only

Returns an RTCSessionDescription object describing a pending configuration change for the local end of the connection. This does not describe the connection as it currently stands, but as it may exist in the near future.

pendingRemoteDescription Read only

Returns an RTCSessionDescription object describing a pending configuration change for the remote end of the connection. This does not describe the connection as it currently stands, but as it may exist in the near future.

remoteDescription Read only

Returns an RTCSessionDescription object describing the session, including configuration and media information, for the remote end of the connection. If this hasn't been set yet, this returns null.

sctp Read only

Returns an RTCSctpTransport object describing the SCTP transport layer over which SCTP data is being sent and received. If SCTP hasn't been negotiated, this value is null.

signalingState Read only

Returns a string describing the state of the signaling process on the local end of the connection while connecting or reconnecting to another peer. It is one of the following values: stable, have-local-offer, have-remote-offer, have-local-pranswer, have-remote-pranswer, or closed.

Static methods

RTCPeerConnection.generateCertificate()

Creates an X.509 certificate and its corresponding private key, returning a Promise that resolves with the new RTCCertificate once it is generated.

Instance methods

Also inherits methods from EventTarget.

addIceCandidate()

Adds a new remote candidate to the RTCPeerConnection's remote description, which describes the state of the remote end of the connection.

addTrack()

Adds a new MediaStreamTrack to the set of tracks which will be transmitted to the other peer.

addTransceiver()

Creates a new RTCRtpTransceiver and adds it to the set of transceivers associated with the connection. Each transceiver represents a bidirectional stream, with both an RTCRtpSender and an RTCRtpReceiver associated with it.

close()

Closes the current peer connection.

createAnswer()

Initiates the creation of an SDP answer to an offer received from a remote peer during the offer/answer negotiation of a WebRTC connection. The answer contains information about any media already attached to the session, codecs and options supported by the browser, and any ICE candidates already gathered.

createDataChannel()

Initiates the creation a new channel linked with the remote peer, over which any kind of data may be transmitted. This can be useful for back-channel content, such as images, file transfer, text chat, game update packets, and so forth.

createOffer()

Initiates the creation of an SDP offer for the purpose of starting a new WebRTC connection to a remote peer. The SDP offer includes information about any MediaStreamTrack objects already attached to the WebRTC session, codec, and options supported by the browser, as well as any candidates already gathered by the ICE agent, for the purpose of being sent over the signaling channel to a potential peer to request a connection or to update the configuration of an existing connection.

getConfiguration()

Returns an object which indicates the current configuration of the connection.

getIdentityAssertion()

Initiates the gathering of an identity assertion and returns a Promise which resolves to an identity assertion encoded as a string. This has an effect only f signalingState is not closed.

getReceivers()

Returns an array of RTCRtpReceiver objects, each of which represents one RTP receiver.

getSenders()

Returns an array of RTCRtpSender objects, each of which represents the RTP sender responsible for transmitting one track's data.

getStats()

Returns a Promise which resolves with data providing statistics about either the overall connection or about the specified MediaStreamTrack.

getTransceivers()

Returns a list of all the RTCRtpTransceiver objects being used to send and receive data on the connection.

removeTrack()

Tells the local end of the connection to stop sending media from the specified track, without actually removing the corresponding RTCRtpSender from the list of senders as reported by getSenders(). If the track is already stopped, or is not in the connection's senders list, this method has no effect.

restartIce()

Allows to easily request that ICE candidate gathering be redone on both ends of the connection. This simplifies the process by allowing the same method to be used by either the caller or the receiver to trigger an ICE restart.

setConfiguration()

Sets the current configuration of the connection based on the values included in the specified object. This lets you change the ICE servers used by the connection and which transport policies to use.

setIdentityProvider()

Sets the Identity Provider (IdP) to the triplet given in parameter: its name, the protocol used to communicate with it and an username. The protocol and the username are optional.

setLocalDescription()

Changes the local description associated with the connection. This description specifies the properties of the local end of the connection, including the media format. It returns a Promise which is fulfilled once the description has been changed, asynchronously.

setRemoteDescription()

Sets the specified session description as the remote peer's current offer or answer. The description specifies the properties of the remote end of the connection, including the media format. It returns a Promise which is fulfilled once the description has been changed, asynchronously.

Obsolete methods

addStream() Deprecated Non-standard

Adds a MediaStream as a local source of audio or video. Instead of using this obsolete method, you should instead use addTrack() once for each track you wish to send to the remote peer.

createDTMFSender() Deprecated

Creates a new RTCDTMFSender, associated to a specific MediaStreamTrack, that will be able to send DTMF phone signaling over the connection.

removeStream() Deprecated Non-standard

Removes a MediaStream as a local source of audio or video. Because this method is obsolete, you should instead use removeTrack().

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

connectionstatechange

Sent when the overall connectivity status of the RTCPeerConnection changes.

datachannel

Sent when the remote peer adds an RTCDataChannel to the connection.

icecandidate

Sent to request that the specified candidate be transmitted to the remote peer.

icecandidateerror

Sent to the connection if an error occurred during ICE candidate gathering. The event describes the error.

iceconnectionstatechange

Sent when the state of the ICE connection changes, such as when it disconnects.

icegatheringstatechange

Sent when the ICE layer's gathering state, reflected by iceGatheringState, changes. This indicates whether ICE negotiation has not yet begun (new), has begun gathering candidates (gathering), or has completed (complete).

negotiationneeded

Sent when negotiation or renegotiation of the ICE connection needs to be performed; this can happen both when first opening a connection as well as when it is necessary to adapt to changing network conditions. The receiver should respond by creating an offer and sending it to the other peer.

signalingstatechange

Sent when the connection's ICE signaling state changes.

track

Sent after a new track has been added to one of the RTCRtpReceiver instances which comprise the connection.

Obsolete events

addstream Deprecated Non-standard

Sent when a new MediaStream has been added to the connection. Instead of listening for this obsolete event, you should listen for track events; one is sent for each MediaStreamTrack added to the connection.

removestream Deprecated Non-standard

Sent when a MediaStream is removed from the connection. Instead of listening for this obsolete event, you should listen for removetrack events on each stream.

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
RTCPeerConnection
56Before Chrome 63, the default value for the configuration.rtcpMuxPolicy parameter is "negotiate" instead of "required".
23
1515 4422 No
43Before Opera 50, the default value for the configuration.rtcpMuxPolicy parameter is "negotiate" instead of "required".
15
11
56Before Chrome 63, the default value for the configuration.rtcpMuxPolicy parameter is "negotiate" instead of "required".
4.4
56Before Chrome 63, the default value for the configuration.rtcpMuxPolicy parameter is "negotiate" instead of "required".
25
4424
43Before Opera Android 46, the default value for the configuration.rtcpMuxPolicy parameter is "negotiate" instead of "required".
14
11
6.0Before Samsung Internet 8.0, the default value for the configuration.rtcpMuxPolicy parameter is "negotiate" instead of "required".
1.5
RTCPeerConnection 5623 1515 4422 No 4315 11 564.4 5625 4424 4314 11 6.01.5
addIceCandidate 24 15
22Starting in Firefox 68, the candidate parameter is optional when calling addIceCandidate(). A null value for candidate indicates no more candidates will be sent, while an empty candidate string indicates that no more candidates will be sent for the current generation of candidates.
No 15 11 4.4 25
24Starting in Firefox 68, the candidate parameter is optional when calling addIceCandidate(). A null value for candidate indicates no more candidates will be sent, while an empty candidate string indicates that no more candidates will be sent for the current generation of candidates.
14 11 1.5
addStream 24 15 22 No 15 11–12 ≤37 25 24 14 11–12 1.5
addTrack 64 79 22 No 51 11 64 64 24 47 11 9.0
addTransceiver 69 79 59 No No 11 69 69 59 No 11 10.0
addstream_event 24 15 22 No 15 No ≤37 25 24 14 No 1.5
canTrickleIceCandidates 83 8315–79 47 No 69 15.4 83 83 47 59 15.4 13.0
close 23 15 22 No 15 11 4.4 25 24 14 11 1.5
connectionState 72 79 113 No 60 11 72 72 113 51 11 11.0
connectionstatechange_event 72 79 113 No 60 11 72 72 113 51 11 11.0
createAnswer 24 15 22 No 15 11 4.4 25 24 14 11 1.5
createDTMFSender 27 79 No No 15 No 4.4 27 No 15 No 1.5
createDataChannel 24 79 22 No 15 11 4.4 25 24 14 11 1.5
createOffer 24 15 22 No 15 11 4.4 25 24 14 11 1.5
currentLocalDescription 70 79 22 No 57 11 70 70 24 49 11 10.0
currentRemoteDescription 70 79 57 No 57 11 70 70 57 49 11 10.0
datachannel_event 25 79 22 No 15 11 4.4 25 24 14 11 1.5
generateCertificate_static 48 79 22 No 35 12.1 48 48 24 35 12.2 6.0
getConfiguration 70 15 22 No 57 11 70 70 24 49 11 10.0
getIdentityAssertion No ≤18–79 40 No No No No No 40 No No No
getLocalStreams 27 15 24 No 15 11–12 ≤37 27 24 15 11–12 1.5
getReceivers 59 79 34 No 46 11 59 59 34 43 11 6.0
getRemoteStreams 27 15 24 No 15 11–12 ≤37 27 24 15 11–12 1.5
getSenders 64 79 34 No 51 11 64 64 34 47 11 6.0
getStats 24 15 27 No 15 11 4.4 25 27 14 11 1.5
getTransceivers 69 79 59 No 56 11 79 69 59 48 11 10.0
iceConnectionState 26 15 24 No 15 11 4.4 26 24 14 11 1.5
iceGatheringState 25 15 22 No 15 11 4.4 25 24 14 11 1.5
icecandidate_event 24 15 22 No 15 11 4.4 25 24 14 11 1.5
icecandidateerror_event 77 79 No No 64 14.1 77 77 No 55 14.5 12.0
iceconnectionstatechange_event 28 15 24 No 15 11 4.4 28 24 15 11 1.5
icegatheringstatechange_event 59 15 22 No 46 11 59 59 24 43 11 7.0
idpLoginUrl No No 40 No No No No No 40 No No No
localDescription 24 15 22 No 15 11 4.4 25 24 14 11 1.5
negotiationneeded_event 24 15 38
24–38Although the onnegotiationneeded property is supported, the negotiationneeded event is never fired.
No 15 11 4.4 25 38
24–38Although the onnegotiationneeded property is supported, the negotiationneeded event is never fired.
14 11 1.5
peerIdentity No ≤18–79 40 No No No No No 40 No No No
pendingLocalDescription 70 79 22 No 57 11 70 70 24 49 11 10.0
pendingRemoteDescription 70 79 22 No 57 11 70 70 24 49 11 10.0
remoteDescription 24 15 22 No 15 11 4.4 25 24 14 11 1.5
removeStream 24 15 22–51 No 15 11–12 ≤37 25 24–51 14 11–12 1.5
removeTrack 64 79 22 No 51 11 64 64 24 47 11 6.0
removestream_event 24 15 22–60 No 15 No ≤37 25 24–60 14 No 1.5
restartIce 77 79 70 No No 14.1 77 77 79 55 14.5 12.0
sctp 76 79 113 No No 15.4 76 76 113 54 15.4 12.0
setConfiguration 48 79 99 No 35 11 48 48 99 35 11 6.0
setIdentityProvider No ≤18–79 40 No No No No No 40 No No No
setLocalDescription 24 15
22Firefox does not support descriptions of type pranswer.
No 15 11 4.4 25
24Firefox does not support descriptions of type pranswer.
14 11 1.5
setRemoteDescription 24 15 22 No 15 11 4.4 25 24 14 11 1.5
signalingState 26 15 24 No 15 11 4.4 26 24 14 11 1.5
signalingstatechange_event 28 15 36
24–36Although the onsignalingstatechange property is supported, the signalingstatechange event is not fired as an Event object. See bug 1075133.
No 15 11 4.4 28 36
24–36Although the onsignalingstatechange property is supported, the signalingstatechange event is not fired as an Event object. See bug 1075133.
15 No 1.5
track_event 64 79 22 No 43 11 64 64 24 43 11 6.0

See also

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https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection