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API that allows web applications to establish interactive, bidirectional, multiplexed network connections

It fills gaps in the web platform:

  • Lack of UDP-like networking API
  • Lack of WebSocket-like API without head-of-line blocking

It provides:

  • Reliable streams
  • Unreliable datagrams
  • Encryption and congestion control
  • An origin-based security model
  • Bindings for QUIC
  • Multiplexing with existing HTTP/3 connections
  • Flexible API that can be extended to other protocols, such as TCP fallback and p2p
  • Ability to change transport without changing application code

It's great for:

  • sending or receiving high-frequency, small messages that don't need to be reliable (like game state)
  • sending or receiving low-latency media
  • transferring files

See the explainer for more info.

See the proposed spec.


Basic Echo

WebCodecs Echo