tags: #publish links: [[Networking]], [[HTTP and related protocols]] created: 2021-09-23 Thu --- # HTTP/3 https://en.wikipedia.org/wiki/HTTP/3 Major revision, following [[HTTP2]], improving transport layer and multiplexing. This evolved out of "HTTP-over-[[QUIC]]". As at 2021: - Status is *Draft* - Draft version is supported by many web browsers already (in some cases, disabled by default) Semantics are preserved. Transport layer changes: ## Use of [[QUIC]] (over UDP) Instead of TCP. This is major change aiming fix limitations of trying to build multiplexing on top of TCP. With TCP, packet loss can then affect all the multiplexed connections, because the lower-level transport layer isn't aware of the multiplexing so can't account for it when recovering from losses.