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Live TLS ALPN negotiation. The result identifies where its evidence came from.
Check whether your web server supports HTTP/2 via TLS ALPN negotiation. Verify protocol speed, cipher suites, and modern browser readiness.
Prześlij publiczny URL, domenę lub słowo kluczowe. Novaverb pokaże tylko dowody, które to narzędzie może faktycznie pobrać lub zmierzyć.
This check proves whether a server actually negotiates HTTP/2 on a real connection, because the protocol is read from the TLS ALPN handshake rather than from any header that claims support. It also reports whether HTTP/3 is advertised. It does not measure speed: negotiating h2 says a connection is multiplexed, not that a page is fast.
Live TLS ALPN negotiation. The result identifies where its evidence came from.
This performs a live TLS handshake and reads the ALPN-negotiated protocol. HTTP/2 requires ALPN; HTTP/3 support is inferred from the Alt-Svc response header, not a QUIC handshake.
Użyj ustalenia, aby zweryfikować problem, a następnie połącz przestrzeń roboczą, gdy potrzebujesz historii, monitorowania lub analizy całej witryny.
Ten sprawdzacz otwiera jedno aktywne połączenie HTTPS, oferuje h2 i http/1.1 przez TLS ALPN, a następnie raportuje protokół wybrany przez punkt końcowy. To czyni werdykt dowodem protokołu - nie zgadywaną oceną ani symulacją przeglądarki.
Sprawdź certyfikat i nazwę hosta SNI, politykę TLS CDN lub load balancera, wsparcie ALPN w stosie TLS oraz czy proxy kończy połączenie przed dotarciem do Twojego źródła.
Wybrany protokół ALPN na jednym nowym połączeniu TLS, plus podstawowy czas połączenia i status HTTP.
Nie gwarantuje szybszych stron, dostępności HTTP/3, wsparcia przeglądarki w każdej sieci ani dobrych Core Web Vitals.
Ten test wykonuje żywe handshake TLS i odczytuje protokół negocjowany ALPN; wsparcie HTTP/3 jest wnioskowane z nagłówka Alt-Svc, a nie handshake QUIC.
Submit the domain or any URL on the site. Only the origin matters, so path and query are normalised away before the handshake. A private host is refused. A CDN in front of the origin answers this check, which is the honest answer for visitors, even when the origin behind it speaks a different protocol.
yourdomain.comKażda forma adresu działa. http lub https, z www lub bez, pusta domena lub pełna ścieżka - normalizujemy to dla Ciebie. Testujemy bezpieczne pochodzenie w każdej sytuacji.https://www.yourdomain.com/pagePełny URL z ścieżką jest w porządku - HTTP/2 to właściwość połączenia, więc sprawdzamy pochodzenie.fast web hostingTo jest fraza wyszukiwania, a nie adres - wprowadź domenę lub URL do testu.The input is normalised to the site's origin and a live TLS handshake is completed. The protocol is taken from the ALPN negotiation, so HTTP/2 is confirmed only when the server genuinely negotiates 'h2'. The Alt-Svc response header is read separately to note whether an HTTP/3 endpoint is advertised alongside it.
Two IETF specifications define this result. RFC 9113 defines HTTP/2 itself, and RFC 7301 defines Application-Layer Protocol Negotiation, the TLS extension this check reads to learn which protocol was actually agreed. Reading ALPN rather than a response header is what makes the answer a measurement instead of a claim.
Potwierdza wsparcie HTTP/2 w sposób wymagany przez protokół: za pomocą ALPN, a nie twierdzenia nagłówka.
Przeczytaj specyfikacjęOdczytuje protokół negocjowany ALPN podczas aktywnej wymiany TLS.
Przeczytaj specyfikacjęIt performs a live TLS handshake and reads the ALPN-negotiated protocol to confirm whether your server actually serves HTTP/2. It also reports the TLS version and whether HTTP/3 is advertised via the Alt-Svc header.
HTTP/2 is a major revision of HTTP that multiplexes many requests over a single connection, adds header compression (HPACK), and enables prioritisation. It reduces round-trip overhead versus HTTP/1.1, speeding delivery of pages with many resources.
Over HTTPS, HTTP/2 is negotiated during the TLS handshake using ALPN (Application-Layer Protocol Negotiation). The client offers h2, and if the server agrees, the connection uses HTTP/2. This test reads exactly that ALPN result.
Enable the HTTP/2 module in your web server or CDN (for example the http2 directive in modern server builds) and ensure HTTPS with ALPN is active. HTTP/2 in browsers effectively requires TLS, so a valid certificate is prerequisite.
HTTP/1.1 sends requests largely one-at-a-time per connection and can suffer head-of-line blocking. HTTP/2 multiplexes concurrent streams over one connection and compresses headers, cutting latency for resource-heavy pages without opening many parallel connections.
No. HTTP/3 here is only inferred from the Alt-Svc response header, which advertises an h3 endpoint. This ALPN-based test confirms HTTP/2 directly but does not perform a QUIC handshake to prove HTTP/3 works.
The specification allows cleartext HTTP/2, but every major browser only supports it over TLS via ALPN. In practice you need a valid certificate and HTTPS for browsers to negotiate and use HTTP/2 at all.
TLS 1.3 is preferred for its faster handshake and stronger defaults, with TLS 1.2 as an acceptable minimum. HTTP/2's blocklist forbids obsolete ciphers, so modern TLS configuration avoids fallback to HTTP/1.1.
Confirm HTTPS with ALPN is enabled and the HTTP/2 module is on at whichever layer terminates TLS, often a CDN or reverse proxy rather than your origin. Some hosts serve HTTP/2 only at the edge.
Indirectly. HTTP/2 can improve real-world load speed by cutting connection overhead, which supports better Core Web Vitals and user experience, factors that influence rankings. It is a performance enabler, not a direct ranking signal by itself.