The read-only property RTCPeerConnection.localDescription returns an RTCSessionDescription describing the session for the local end of the connection. If it has not yet been set, this is null.


 var sessionDescription = peerConnection.localDescription;

On a more fundamental level, the returned value is the value of RTCPeerConnection.pendingLocalDescription if that property isn't null; otherwise, the value of RTCPeerConnection.currentLocalDescription is returned. See Pending and current descriptions in WebRTC connectivity for details on this algorithm and why it's used.


This example looks at the localDescription and displays an alert containing the RTCSessionDescription object's type and sdp fields.

var pc = new RTCPeerConnection();
var sd = pc.localDescription;
if (sd) {
  alert("Local session: type='" +
        sd.type + "'; sdp description='" +
        sd.sdp + "'");
else {
  alert("No local session yet.");


WebRTC 1.0: Real-Time Communication Between Browsers (WebRTC 1.0)
# dom-peerconnection-localdescription

Browser compatibility

BCD tables only load in the browser

See also