WebTransport API

[o-t-w]

Description

The WebTransport API provides a modern alternative to WebSockets, transmitting data between client and server using HTTP/3 Transport. WebTransport provides support for multiple streams, unidirectional streams, and out-of-order delivery. It enables reliable transport via streams and unreliable transport via UDP-like datagrams.

Specification

https://w3c.github.io/webtransport/

Additional Signals

WebTransport is enabled in Firefox and Chrome/Edge/Samsung Internet.
WebKit have expressed a positive position on the standard.
Some initial work was merged on WebKit’s implementation.

Firefox bug
Chromium bug

Tests: https://wpt.fyi/results/?label=master&label=experimental&aligned&view=subtest&q=webtransport

[mehagar]

Of particular interest to me is the congestionControl parameter: https://developer.mozilla.org/en-US/docs/Web/API/WebTransport/congestionControl , which would make it possible to specify the congestion control would be optimized for low latency solutions. This is relevant if WebTransport is to replace use of WebRTC DataChannels for media transport.

[lilnasy]

I would love to see WebTransport become a focus area as well!

Progressive enhancement with WebTransport isn't practical. For applications to abstract its API and use WebSocket when it is unavailable is non trivial. Which is why I believe it needs to become cross-browser before we see significant adoption and development of the server-side and client-side ecosystem.