/Web APIs

RTCSessionDescription: type property

The property RTCSessionDescription.type is a read-only string value which describes the description's type.


const value = sessionDescription.type
sessionDescription.type = value


The possible values are:


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.


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.


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.


This special type with an empty session description is used to roll back to the previous stable state.


// The remote description has been set previously on pc, a RTCPeerConnection



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
type 23 15 22 No 15 11 4.4 25 24 14 11 1.5

See also

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