Web/API/RTCSessionDescription/RTCSessionDescription

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

DeprecatedThis feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The RTCSessionDescription() constructor creates a new RTCSessionDescription with its properties initialized as described in the specified object.

This constructor has been deprecated because RTCPeerConnection.setLocalDescription() and other methods which take SDP as input now directly accept an object conforming to the RTCSessionDescriptionInit dictionary, so you don't have to instantiate an RTCSessionDescription yourself.

Syntax

 sessionDescription = new RTCSessionDescription(rtcSessionDescriptionInit);

Values

rtcSessionDescriptionInit ' Optional

An object providing the default values for the session description; the object conforms to the RTCSessionDescriptionInit dictionary. That dictionary has the following properties:

type

Required. A string which is a member of the RTCSdpType enum; it must have one of the following values:

This enum defines strings that describe the current state of the session description, as used in the type property. The session description's type will be specified using one of these values.

Value	Description
`answer`	The SDP contained in the `sdp` property is the definitive choice in the exchange. In other words, this session description describes the agreed-upon configuration, and is being sent to finalize negotiation.
`offer`	The session description object describes the initial proposal in an offer/answer exchange. The session negotiation process begins with an offer being sent from the caller to the callee.
`pranswer`	The session description object describes a provisional answer; that is, a response to a previous offer that is not the final answer. It is usually employed by legacy hardware.
`rollback`	This special type with an empty session description is used to roll back to the previous stable state.

sdp

A string containing a SDP message describing the session. This value is an empty string ("") by default and may not be null.

Example

This example uses the constructor to convert an SDP offer into an RTCSessionDescription object.

This is no longer necessary, however; RTCPeerConnection.setLocalDescription() and other methods which take SDP as input now directly accept an object conforming to the RTCSessionDescriptionInit dictionary, so you don't have to instantiate an RTCSessionDescription yourself.

navigator.getUserMedia({video: true}, function(stream) {
  pc.onaddstream({stream: stream});
  // Adding a local stream won't trigger the onaddstream callback
  pc.addStream(stream);

  pc.createOffer(function(offer) {
    pc.setLocalDescription(new RTCSessionDescription(offer), function() {
      // send the offer to a server to be forwarded to the friend you're calling.
    }, error);
  }, error);
}

Specifications

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

Browser compatibility

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
`RTCSessionDescription()` constructor Experimental'Deprecated'	Chrome Full support Yes	Edge Full support ≤18	Firefox Full support Yes Prefixed' Full support Yes Prefixed' Prefixed' Implemented with the vendor prefix: moz	IE No support No	Opera ?	Safari ?	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android ?	Opera Android ?	Safari iOS ?	Samsung Internet Android Full support Yes

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.
Deprecated. Not for use in new websites.': Deprecated. Not for use in new websites.
Requires a vendor prefix or different name for use.': Requires a vendor prefix or different name for use.