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
![QUIC and HTTP/3 Support now in Firefox Nightly and Beta – Mozilla Hacks - the Web developer blog](https://cdn-ak-scissors.b.st-hatena.com/image/square/6282fee8d6c4fbd7c3553a5c6d4ac8ed287a5981/height=288;version=1;width=512/https%3A%2F%2Fhacks.mozilla.org%2Ffiles%2F2021%2F04%2Ffirefox-h3-about-config.png)