1. Bron
Live QUIC handshake + Alt-Svc. The result identifies where its evidence came from.
Test whether your web server supports HTTP/3 over QUIC with a live handshake probe. Verify Alt-Svc headers and next-gen protocol performance.
Dien een openbare URL, domein of zoekwoord in. Novaverb toont alleen het bewijs dat deze tool daadwerkelijk kan ophalen of meten.
This check proves whether a real HTTP/3 request over QUIC succeeds, not merely whether HTTP/3 is advertised. Support is reported only when an actual h3 response comes back, so an Alt-Svc header pointing at an endpoint that never answers is reported as advertised and unconfirmed rather than as support.
Live QUIC handshake + Alt-Svc. The result identifies where its evidence came from.
This attempts a real QUIC connection offering ALPN h3 and also reads the Alt-Svc discovery signal. Confirmed means a live HTTP/3 handshake completed; advertised means h3 was announced but not confirmed here.
Gebruik de bevinding om een probleem te verifiëren, verbind vervolgens een werkruimte wanneer je geschiedenis, monitoring of site-brede analyse nodig hebt.
HTTP/3 draagt HTTP over QUIC, een op UDP gebaseerde transport. Deze checker leest eerst het live HTTPS-ontdekkingssignaal, probeert vervolgens een echte QUIC-handshake en HTTP/3-aanroep. Het resultaat scheidt een geadverteerde mogelijkheid van een bevestigde.
Controleer UDP-bereikbaarheid, CDN-edgebeleid, certificaat/SNI-configuratie en of de probe wordt geblokkeerd. Een Alt-Svc-header alleen bewijst niet dat QUIC kan voltooien.
Een echte QUIC + HTTP/3 handshake wanneer bevestigd, of een duidelijk gelabeld ontdekkingssignaal wanneer alleen h3 wordt geadverteerd.
Het meet geen paginasnelheid, Core Web Vitals, elke geografische rand, of HTTP/3-gebruik door alle bezoekers.
"Bevestigd" betekent dat een live HTTP/3 (QUIC) handdruk is voltooid; "Aangeboden" betekent dat h3 is aangekondigd via Alt-Svc maar niet bevestigd door deze controle.
Submit the domain or any URL on the site; only the origin is used. A private host is refused. Bear in mind that HTTP/3 travels over UDP, so a network that blocks QUIC will make a site that genuinely supports it look unsupported from that vantage point, which is a property of the path rather than of the server.
yourdomain.comElke adresvorm werkt. http of https, met of zonder www, een blote domein of een volledige pad - we normaliseren het voor je.https://www.yourdomain.comHTTP/3 rijdt op QUIC over UDP 443; we lossen de oorsprong op en proberen het direct.Reading 'unsupported' as a tool errorAls UDP 443 gefilterd is op het pad, kan een echte h3-aanvraag niet worden voltooid - 'unsupported' is dan de juiste bevinding, geen bug.The Alt-Svc header is read first, because that is how an h3 endpoint is discovered. A real HTTP/3 request is then attempted over QUIC against that endpoint, and the result is reported as supported only when an actual h3 response is received. Advertisement and confirmation are kept as separate findings throughout.
Three IETF specifications define this result. RFC 9114 defines HTTP/3, RFC 9000 defines the QUIC transport it runs on, and RFC 7838 defines the Alt-Svc header used for discovery. Separating discovery from confirmation follows directly from RFC 7838, which describes an advertisement rather than a guarantee.
Voltooit een echte HTTP/3 aanvraag om ondersteuning te bevestigen, niet alleen een advertentie.
Lees de specificatieOpent een QUIC-verbinding over UDP als het transport voor HTTP/3.
Lees de specificatieLeest de Alt-Svc header die een h3-eindpunt adverteert voor ontdekking.
Lees de specificatieIt attempts a real QUIC connection offering ALPN h3 to confirm your server actually speaks HTTP/3, and separately reads the Alt-Svc header to report whether an h3 endpoint is merely advertised.
HTTP/3 is the latest HTTP version, defined in RFC 9114, running over QUIC instead of TCP. QUIC uses UDP, integrates TLS 1.3, and eliminates TCP head-of-line blocking, improving performance on lossy or high-latency networks.
Confirmed means a live HTTP/3 handshake over QUIC actually completed in this test. Advertised means your server announced an h3 option in the Alt-Svc header, but this test did not verify that endpoint responds.
QUIC is a transport protocol over UDP that combines connection setup with TLS 1.3 encryption and supports stream multiplexing without head-of-line blocking. HTTP/3 is HTTP mapped onto QUIC, so confirming HTTP/3 means completing a QUIC handshake.
A server sends an Alt-Svc response header advertising an h3 endpoint, telling clients they may retry over QUIC. Browsers typically connect first over HTTP/2, read Alt-Svc, then upgrade to HTTP/3 on subsequent requests.
Enable QUIC and HTTP/3 in your web server or CDN, allow inbound UDP on port 443 through firewalls, and emit an Alt-Svc header advertising h3. Many sites get HTTP/3 simply by enabling it at their CDN edge.
Often UDP 443 is blocked by a firewall, the QUIC listener is misconfigured, or only the edge speaks h3 intermittently. Advertising via Alt-Svc is a promise; a failed QUIC handshake means clients quietly fall back to HTTP/2.
Not strictly. HTTP/3 mainly helps users on unreliable or high-latency mobile networks by surviving packet loss and network changes better than TCP. It is a worthwhile enhancement rather than a replacement for a working HTTP/2 setup.
Yes. QUIC integrates TLS 1.3 directly into the transport, so HTTP/3 is always encrypted by design. There is no cleartext HTTP/3, and a valid certificate is required for the handshake this test performs.
Only indirectly. Faster, more resilient connections can improve real-user load times and Core Web Vitals, which support rankings. HTTP/3 itself is not a direct ranking factor, and confirming it mainly future-proofs your delivery on modern networks.