🚀 HTTP/2 Checker

Check if a website supports HTTP/2 protocol for improved performance and speed.

Enter Domain:

💡 Tip: Enter a domain and click "Check HTTP/2" to verify support.

Enter a domain and click "Check HTTP/2" to view results.

How support is established

Enter a domain and our server opens a real connection to it and reports which protocol the two ends settled on. The decision happens inside the TLS handshake, in an extension called ALPN: the client lists what it speaks, the server picks one, and the choice is made before a single byte of HTTP is sent.

client offers:  h2, http/1.1
server selects: h2          -> HTTP/2 supported

Which is why the answer is yes or no with nothing in between. The protocol is negotiated per connection, not configured per page, so it is a property of the server and the hostname you tested - not of the site as a whole. A CDN in front of an origin can speak HTTP/2 to visitors while talking HTTP/1.1 to the origin behind it, and this reports the half you are asking about.

What changes once it is on

One connection carries every request at once instead of six connections taking turns, and repeated headers - cookies, user-agent, accept lines resent in full on every HTTP/1.1 request - are compressed away. On a page of eighty small assets over a slow link, that is the whole difference. On one large download it is nothing.

The awkward part is that HTTP/2 makes several old habits harmful:

Domain sharding - splitting assets across img1, img2 and so on to escape the six connection limit. Now it just forces extra handshakes.
Bundling everything into one file - still helps compression, but no longer worth breaking caching for, since a hundred small files cost little.
Server push - part of the standard, but Chrome removed support in 2022. Use rel="preload" instead.

Google does not rank a site for speaking HTTP/2. What it measures is the loading experience the visitor gets, through Core Web Vitals - and on an asset-heavy page over mobile latency, the protocol moves those numbers.

Frequently asked questions

Does HTTP/2 require HTTPS?

The specification allows a cleartext form, h2c, but no major browser has ever implemented it. In practice HTTP/2 means TLS, because the negotiation lives in the TLS handshake. A site served over plain HTTP will always come back as unsupported here.

Is HTTP/2 actually faster?

On pages with many resources and a visitor far from the server, clearly so - the requests overlap instead of queueing. On a page with a handful of files on a fast local link, the difference is hard to measure. It is a change in how requests are carried, not in how much data crosses the wire.

Do I have to change my site to turn it on?

No. HTTP/2 carries the same methods, headers and status codes, so nothing in your application code is aware of it. It is enabled in the web server or at the CDN, and every managed host worth using has had it on by default for years. The only work is undoing HTTP/1.1 workarounds that now cost you.