demo · v143 · webrtc

SDP diff tool

Build a real RTCPeerConnection, toggle which RTP header extensions to negotiate, run two offer / answer rounds, and diff the resulting SDP. Lines highlighted green are added, red are dropped. v143 keeps the user's preferences sticky across rounds — pre-v143 silently re-enabled extensions on the second round.

Extension controls

round 1 SDP (offer)


    

    

      
round 2 SDP (offer)

      

    

  


  
Run round 1, then untick an extension, then run round 2 to see the diff.


  
What you're looking at

  
    
    
  1. Each tile is an RTP header extension. Tick / untick to control which the negotiation includes.
    2. 
    
  2. Round 1 picks the extensions and runs setLocalDescription / setRemoteDescription.
    3. 
    
  3. Untick one extension between rounds and run round 2. Pre-v143 Chrome would re-add it; v143 keeps it removed.
    4. 
    
  4. The verdict box compares round 1 vs round 2 and tells you whether your browser implements the sticky behaviour.
    5. 
  


  
// v143-friendly
transceiver.setHeaderExtensionsToNegotiate(
  current.filter(ext => userWantsExtension(ext.uri))
);
// On the next offer, dropped extensions stay dropped.


  

    
see also