Example: https://sellbuystuffs.com is HTTP/3 Enabled Website
Enter Multiple Website to Test HTTP/3 in Bulk
HTTP3 is advanced and New Protocol version, and it is the fastest protocol as compared to HTTP/2 and HTTP/1.1
If your Website or Hosting supports HTTP/3 than your Website will load faster as compared to other Protocol.
Above Test will make a CURL request to your website and will check the Header response if your Website can support HTTP/3 version or not.
One Example of HTTP3 Header Response : alt-svc h3-24=":443"; ma=86400, h3-23=":443"; ma=86400 that confirms your website supports HTTP/3 Protocol.