WebRTC Unified Plan SDP

RTCPeerConnections generate and parse SDP according to the standardized format. Exchanging SDP is needed to set up calls in WebRTC. Following the standard is important for cross-browser interoperability. Unified Plan also enables the RTCRtpTransceiver APIs. Changing from the old ("Plan B") to the new format can cause backwards-compatibility issues or break applications, see the Transition Guide: https://docs.google.com/document/d/1-ZfikoUtoJa9k-GZG1daN0BU3IjIanQ_JSscHxQesvU/edit?usp=sharing


Since Chrome 65, this has been an experimental feature that you can opt-in to by passing sdpSemantics:'unified-plan' to the RTCPeerConnection constructor, with transceivers added in M69. History: https://crbug.com/799030. Canary/Dev experiments making Unified Plan the default behavior started in 71. The target is to release Unified Plan by default in 72 Stable. For more information, see https://webrtc.org/web-apis/chrome/unified-plan/.



Working draft or equivalent

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 72
  • Chrome for Android release 72
  • Android WebView release 72

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • Shipped
  • Public support
  • In development
  • Positive


Last updated on 2019-01-24