HTTP/2 + HTTP/3 Test

Click Check HTTP protocol support Detect whether your browser is using HTTP/2 or HTTP/3 right now.

Protocol snapshot

HTTP/2 and HTTP/3 test

See which HTTP protocol your browser negotiates for requests.

Ready to test

Results reflect the current page and a fresh test request from your browser.

Protocol results

Run the test to detect the active protocol.

Current pageUnknown

Test requestUnknown

Response time--

If HTTP/3 is not shown, your browser, network, or server may not support it yet.

Why run an HTTP/2 and HTTP/3 test

An HTTP/2 and HTTP/3 test helps you verify which protocol your browser negotiates for requests. This is useful when troubleshooting performance, CDN behavior, or compatibility issues across networks and devices.

How the test runs

The tool reads the browser’s resource timing data for the current page and a fresh request to the site. It reports the negotiated protocol without changing any settings or sending data to third parties.

How to interpret results

Use the detected protocol to understand how your browser is connecting. HTTP/3 requires browser, server, and network support, so it may not appear even if the browser supports it.

HTTP/2 is still common and fully supported across modern browsers.
HTTP/3 can be blocked by networks that limit UDP traffic.
Results can change depending on the server or CDN configuration.

This test does not enable protocols or validate TLS settings. It only reports the protocol negotiated for the measured requests.

Frequently Asked Questions

What is an HTTP/2 and HTTP/3 test?

An HTTP/2 and HTTP/3 test reports which protocol your browser uses for a request. It helps confirm protocol support for the current connection.

How does the HTTP/2 HTTP/3 test work in the browser?

The test reads browser resource timing data for the current page and a fresh request. It uses those timings to show the negotiated protocol.

Does the HTTP/2 HTTP/3 test show protocol for this site only?

Yes, it reflects the protocol used to reach this site and the test endpoint. Other sites may negotiate different protocols.

Why does the HTTP/2 HTTP/3 test show HTTP/1.1?

HTTP/1.1 can appear when HTTP/2 or HTTP/3 is not available for the request. This may be due to server configuration, network restrictions, or browser settings.

Is HTTP/3 always available when the browser supports it?

No, HTTP/3 also requires server support and a network path that allows UDP. Some networks or firewalls can block it.

Is the HTTP/2 HTTP/3 test safe and private?

The test only checks protocol information for requests to this site. It does not access files or store results.

Does the HTTP/2 HTTP/3 test work on mobile?

Yes, it works on modern mobile browsers. Results can vary by carrier and network conditions.

Why might HTTP/2 HTTP/3 test results differ from other tools?

Different tools may test different hosts, caches, or endpoints. Protocol negotiation can change based on server location and configuration.

What can the HTTP/2 HTTP/3 test not do?

It cannot enable HTTP/3 or fix server configuration. It only reports the protocol negotiated for the measured requests.

How accurate is the protocol detection?

It is accurate for the specific requests measured by the browser at the time of the test. It does not guarantee protocols for other sites or future sessions.