I have been searching the web but I can't find any test to see if the browser I'm using is currently supporting HTTP/3 and if it is enabled. The websites I find are only for testing if websites support HTTP/3. Is there any website for testing if a browser supports HTTP/3?
You can test if your browser supports HTTP/3 at quic.nginx.org which is hosted by NGINX.
This is what it looks like for me:
You can also use http3.is by Fastly. I had to reload the page for it to work.
This is what http3.is looks like for me (with HTTP/3 supported):
Cloudflare offers a HTTP/3 test at cloudflare-quic.com but it might also require a page reload before it works.
This is what it looks like for me after a reload (with HTTP/3 supported):