tl;dr: Support for QUIC and HTTP/3 is now enabled by default in Firefox Nightly and Firefox Beta. We are planning to start rollout on the release in Firefox Stable Release 88. HTTP/3 will be available by default by the end of May. What is HTTP/3? HTTP/3 is a new version of HTTP (the protocol that powers the Web) that is based on QUIC. HTTP/3 has three main performance improvements over HTTP/2: Bec