My site is now being served with HTTP/3, which automatically means it’s being served over QUIC, but what does that mean?

Originally called “HTTP over QUIC” was later renamed to “HTTP/3” to make clear it’s the new thing. But it’s a pity QUIC isn’t mentioned anymore because that’s the amazing part, really!

You see, while HTTP has so far sat on top of TCP, HTTP/3 sits on top of QUIC, a protocol developed at Google, that sits on top of UDP!

Highlights of QUIC are things like reducing latency and to be non-blocking. It has encryption in mind and reduces the back and forth between client and server when setting up encryption. TCP and UDP are implemented in the kernel while QUIC sits on top of UDP and is at the application level, which means it can be adapted and expanded more easily if needed.

So, basically QUIC tries to be QUICK! And HTTP/3 sits on top of it.

Now, while HTTP/3 is not yet officially a released standard, it’s already found in many browsers in some form and although not enabled by default, it can be enabled easily in Firefox.

Enable HTTP/3 in Firefox

In your address bar, type about:config and hit enter and “Accept the Risk and Continue”, then look for the option network.http.http3.enabled and set it to true.

Other Browsers

Other browsers either only provide HTTP/3 in their development/beta builds or require a command line parameter to enable HTTP/3 which makes it unpractical for daily use. So if you want to use HTTP/3 I recommend using Firefox, which I recommend either way.

Testing HTTP/3

After enabling HTTP/3 open your developer tools in your browser (F12 in Firefox) and go to the “Network” tab, refresh the page and click on some request to my site and check the “Headers” on the right and you should see Version: HTTP/3!

That’s all there is to it!