The SDP used to establish a connection in WebRTC has a non-standard dialect: Plan B. Removal timeline: M93: Exception thrown in Canary. M96: Exception thrown in Beta and Stable. There is a Deprecation Trial to avoid the exception until May 25, 2022 ( The End Date was previously December 29. To get new new End Date, a new OT token is needed. First version with Plan B removed: M102.


Plan B is Chromium-only and has compatibility issues with for example Safari and Firefox. Some features are not available in Plan B. Unified Plan has been shipped-by-default since M72. WebRTC is now a W3C Recommendation.


Specification link

Specification being incubated in a Community Group

Status in Chromium


Origin trial (tracking bug)

Consensus & Standardization

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

  • Shipped/Shipping
  • Shipped/Shipping
  • No signals


Search tags

WebRTC SDP Plan B Unified Plan,

Last updated on 2022-05-15