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HTTP/3 Tester

Check whether a website supports HTTP/3 over QUIC.

How to use it

  1. 01

    Enter a URL

    Use the full address, like https://example.com.

  2. 02

    Run the test

    We request the page and read whether the server advertises HTTP/3 (its Alt-Svc header), as browsers do.

  3. 03

    Read the result

    See how support is advertised and the response time.

Questions

What is HTTP/3?

The newest version of HTTP. It runs over QUIC instead of TCP, which helps on slow or unreliable connections.

How do browsers find HTTP/3?

Usually through an alt-svc header on an HTTP/2 response, or a DNS HTTPS record.

Do I need HTTP/3?

It is not required, but it can make your site faster for mobile visitors. Many CDNs offer it with one switch.