WebTransport is a protocol framework that enables clients constrained by the Web security model to communicate with a remote server using a secure multiplexed transport.


Currently, Web application developers have two APIs for bidirectional communications with a remote server: WebSockets and RTCDataChannel. WebSockets are TCP-based, thus having all of the drawbacks of TCP that make it a poor fit for latency sensitive applications (head of line blocking, lack of support for unreliable data transport). RTCDataChannel is based on SCTP, which does not have these drawbacks; however, it is designed to be used in a peer-to-peer context, which caused its use in client-server settings to be fairly low. WebTransport provides a client-server API that supports bidirectional transfer of both unreliable and reliable data, using UDP-like datagrams and cancellable streams.



Specification link

Unknown standards status - check spec link for status

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.


Intent to Prototype url

Intent to Prototype thread

Search tags

webtransport, udp websocket,

Last updated on 2021-11-28