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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.
Envía una URL pública, dominio o palabra clave. Novaverb mostrará solo la evidencia que esta herramienta puede realmente recuperar o medir.
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.
Usa el hallazgo para verificar un problema, luego conecta un espacio de trabajo cuando necesites historial, monitoreo o análisis a nivel de sitio.
Este verificador abre una conexión HTTPS en vivo, ofrece h2 y http/1.1 a través de TLS ALPN, y luego informa el protocolo seleccionado por el punto final. Eso hace que el veredicto sea evidencia del protocolo - no una puntuación adivinada o una simulación de navegador.
Verifica el certificado y el nombre de host SNI, la política TLS del CDN o balanceador de carga, el soporte ALPN en la pila TLS y si un proxy está terminando la conexión antes de que llegue a tu origen.
El protocolo ALPN seleccionado en una nueva conexión TLS, más el tiempo de conexión básico y el estado HTTP.
No garantiza páginas más rápidas, disponibilidad de HTTP/3, soporte de navegador en cada red, o buenos Core Web Vitals.
Esta prueba realiza un apretón de manos TLS en vivo y lee el protocolo negociado por ALPN; el soporte para HTTP/3 se infiere del encabezado Alt-Svc, no de un apretón de manos 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.comCualquier forma de dirección funciona. http o https, con o sin www, un dominio desnudo o una ruta completa - lo normalizamos por ti. Probamos el origen seguro de cualquier manera.https://www.yourdomain.com/pageUna URL completa con una ruta está bien - HTTP/2 es una propiedad de conexión, así que verificamos el origen detrás de ella.fast web hostingEsa es una frase de búsqueda, no una dirección - ingresa un dominio o URL para probar.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.
Confirma el soporte de HTTP/2 de la manera que requiere el protocolo: a través de ALPN, no una afirmación de encabezado.
Lee la especificaciónLee el protocolo negociado por ALPN durante el apretón de manos TLS en vivo.
Lee la especificaciónIt 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.