WebTransport is an upcoming protocol (standardized by the IETF) and Web API (standardized by the W3C) for bidirectional communication on the web. It provides multiplexed streams and unreliable datagrams on top of HTTP/3 and HTTP/2.

This talk explains how WebTransport works at the protocol level, how it maps to QUIC when run on top of HTTP/3, and how its capabilities differ from WebSocket. The session will also cover the current state of browser and server support, and where the ecosystem is heading next.