New. Onion Domain

HTTP Protocol Checker

Check if a website supports HTTP/2 and HTTP/3. Modern protocols mean faster, more secure connections.

How it works

The check runs in real time against the live server.

Enter a URL

Paste any publicly accessible website URL. No signup, no setup.

Live negotiation

We perform a real protocol negotiation with the target server, not just a header check.

Instant result

Clear pass/fail indicators for HTTP/1.1, HTTP/2, and HTTP/3 in under a second.

Why HTTP/2 and HTTP/3 matter

Performance improvements that make a real difference on real networks.

HTTP/2

Revolutionized web performance with multiplexing, header compression, and server push. Widely supported and a meaningful speed improvement over HTTP/1.1.

HTTP/3

Built on QUIC instead of TCP. Eliminates head-of-line blocking, cuts connection setup time, and performs better on mobile and unreliable networks.

Global protocol usage

Data from last 7 days.

Apr 28, 2026

  • HTTP/1.x
    27.7%

    Legacy protocol still in use

  • HTTP/2
    51.1%

    Most widely adopted modern protocol

  • HTTP/3
    21.2%

    Next-generation protocol, rapidly growing