It doesn’t seem like HTTP/2 has really been mainstream that long, but along has come HTTP/3, brand new and bleeding edge.

HTTP/2 itself is much quicker than HTTP/1.1 because it allows TCP connections to be multiplexed, meaning more than one file can be sent through the same connection at the same time  (called “streams”).  It’s a TCP connection using TLS, which means that in order for a connection to be made there is a lot of handshaking in order to establish the encryption and other protocols required for communication.

HTTP/3 however does not use TCP, it uses QUIC, which is essentially an extension of UDP.  This does not require the same start up cost in terms of handshaking, and is therefore much quicker to initialise.  It also uses a different header compression algorithm, specifically designed to allow the different streams to return in different orders.

Chrome and Firefox has announced that they will be supporting this new protocol, and have been working with Cloudflare to make it a reality.  It can already be enabled in Chrome Canary (the early development releases) using command line switches.

To get ahead of the game, log into your Cloudflare dashboard, go to the “Network” tab and where it says “HTTP/3 (with QUIC) [BETA]” click the “Join Waitlist” button.

If you got in there really early, some accounts have already been granted access to enable this feature.  But it’s rolling out slowly, so the sooner you add yourself to the waitlist the better.

For more details, read their blog post; HTTP/3: the past, the present, and the future.