HTTP/3 test: check if your site serves HTTP/3 and HTTP/2
This HTTP/2 and HTTP/3 test shows which protocol your server picks, whether HTTP/3 is advertised, and which files on the page, yours or third-party, still load over HTTP/1.1.
- Free, no account
- Results in under a minute
- Every file on the page, by protocol
Example result:example-shop.hr
WordPress 6.8Sample shop · homepage · mobile Chrome · the same check you get for your own site
Detected technology
- WordPress 6.8
- WooCommerce
- Elementor
- jQuery 1.12.4
- LiteSpeed
Protocol
| HTTP/2 (ALPN) | not tested (plain http) |
|---|---|
| HTTP/3 (Alt-Svc) | not advertised |
| Alt-Svc header | - |
| TLS | - |
| Responses by protocol (Chromium) | http/1.1: 15 |
What we found
Show 1 passed check
Fix these first
From the example above. Check your own site to get the fixes that apply to it.
Problem: The site is served over HTTP, not HTTPS
Browsers label HTTP pages "Not secure" and Google ranks HTTPS pages higher.
How to fix it: Get a certificate (Let's Encrypt is free) and enable HTTPS on your host.Warning: 11 text files are sent uncompressed
HTML, CSS and JavaScript shrink 3–5× with gzip or Brotli.
How to fix it: Enable Brotli (or gzip) for text types in your server, hosting panel or CDN; Cloudflare and most hosts have it as one switch.Warning: 15 requests still use HTTP/1.1
HTTP/2 and HTTP/3 load many files over one connection at once; HTTP/1.1 queues them six at a time.
How to fix it: Turn on HTTP/2 or HTTP/3 in your hosting or CDN panel; on Cloudflare and most managed hosts it is a checkbox.
What the HTTP/2 and HTTP/3 test checks
Protocol, compression, caching and CDN checks, because they are usually set in the same place.
HTTP/2 server support
Checks your server offers HTTP/2, a setting that makes pages with many files load faster.
HTTP/3 advertised
Checks your server announces HTTP/3, which connects faster and copes better with flaky mobile networks.
HTTP/2 or HTTP/3 requests
Finds requests still on HTTP/1.1, which loads files slowly in small batches instead of all at once.
Text compression
Checks HTML, CSS and JavaScript are compressed with Brotli or gzip, saving visitors data and time.
Cache lifetime for static files
Checks images, CSS and scripts can be cached, so returning visitors do not download them again.
CDN in front of the site
Checks for a CDN, which serves files from near each visitor and absorbs traffic spikes.
Minimum TLS version
Checks the server refuses old TLS 1.0 and 1.1, which attackers can use to weaken a connection.
HTTPS connection
Checks the site is served over HTTPS, so browsers don't label it "Not secure" and visits stay private.
Show 4 more checks
Cache lifetime for static files
Checks images, CSS and scripts can be cached, so returning visitors do not download them again.
CDN in front of the site
Checks for a CDN, which serves files from near each visitor and absorbs traffic spikes.
Minimum TLS version
Checks the server refuses old TLS 1.0 and 1.1, which attackers can use to weaken a connection.
HTTPS connection
Checks the site is served over HTTPS, so browsers don't label it "Not secure" and visits stay private.
How the HTTP/2 and HTTP/3 test works
Run a TLS handshake
We connect with ALPN offering h2 and http/1.1 and record the protocol the server picks, with the TLS version and cipher.
Read Alt-Svc
The Alt-Svc header of the page response tells whether HTTP/3 is advertised for the next visit.
Load every file
The page is loaded in Chromium and every response is grouped by protocol (h3, h2, http/1.1), so you also see third-party files still on HTTP/1.1.
We report the first-visit handshake. A browser that has seen the Alt-Svc header before can switch to HTTP/3 on its next visit, which the handshake alone does not show.
HTTP/2 and HTTP/3 questions
Can this test explain an ERR_HTTP2_PROTOCOL_ERROR or ERR_QUIC_PROTOCOL_ERROR?
It tells you which side to look at. If the test negotiates HTTP/2, advertises HTTP/3 correctly and loads the page, the server side works, and the error usually comes from the visitor's device: an extension, antivirus that inspects HTTPS, a VPN or a network that blocks UDP. If the test fails too, the server or CDN setup is the cause. Our guides on each error walk through the fixes.
How do I enable HTTP/2 on my server?
Serve the site over HTTPS first, since browsers use HTTP/2 only with TLS. On nginx 1.25.1 or newer add http2 on; to the server block (older versions: listen 443 ssl http2;), and on Apache enable mod_http2 and add Protocols h2 http/1.1. Most hosts and every major CDN, including Cloudflare, already serve HTTP/2. Reload the server and run the test again.
HTTP/3 vs HTTP/2: what changes for my site?
HTTP/3 keeps HTTP/2's features but swaps TCP for QUIC over UDP. Connections start faster, a lost packet no longer holds up every other file, and a connection can survive a switch from Wi-Fi to mobile data. The gains are largest on slow or unstable networks. Browsers try HTTP/3 only after an Alt-Svc header announces it, so a first visit usually uses HTTP/2.
How do I check if HTTP/2 is enabled?
Enter the site above. The test connects with ALPN offering h2 and http/1.1 and reports what the server picks, then loads the page in Chromium and groups every file by protocol. In your own browser, open the developer tools, go to the Network tab and add the Protocol column: h2 means HTTP/2 and h3 means HTTP/3.
The test says HTTP/2 but my browser shows h3. Which is right?
Both. ALPN is negotiated once per connection; a browser that has seen the Alt-Svc header before switches to HTTP/3 on its next visit. The tool reports the first-visit handshake and whether HTTP/3 is advertised, so a pass on both means returning visitors get HTTP/3.
Is this HTTP/2 and HTTP/3 test free?
Yes, with no sign-up. getReport is funded by donations, not plans, and the complete report with all seven modules is one click away, also free. It stays at its shareable link for 12 months, is not listed publicly and carries a noindex tag, and nothing about your visitors is collected.
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