HTTP/3 Check - QUIC Browser Test

Test your website and browser for HTTP/3 and QUIC protocol support online - Free browser check tool

Public HTTPS endpoints on port 443 only. Checks are rate limited; please wait if the checker is busy. TLS certificates must be valid.

cloudflare.com

check_circle QUIC is advertised or negotiated

check_circle HTTP/3 is advertised or negotiated

HTTP/3 was advertised in the response headers or negotiated for this check. The negotiated protocol was HTTP/3. This check does not measure QUIC connection IDs, packet timing or 0-RTT.

HTTP/3 Server Information

HTTP Version: HTTP/3
Server: cloudflare
Status Code: 301
Response Time: 25.62 ms

Response Headers

Header Value
content-type text/html; charset=UTF-8
date Tue, 20 Oct 2026 22:20:16 GMT
location https://www.cloudflare.com/
strict-transport-security max-age=15780000; includeSubDomains
set-cookie __cf_bm=fqMNcjNev8sRgUNqbLyg2RT7O9bTH8JH8uZuctncVko-1792534816.7366369-1.0.1.1-iY5jkRUuh4FOfimhijXDcPQRUdhCjVMNc73dFeksF89yjrloqEjqUxnLfJfdRU6h_DD8AnEr5Yf7coh6r3HZPCisHQx.mH.CJaNzhxGGGFD.uzy7TQ02Oeeqxd3KZW.y; HttpOnly; Secure; Path=/; Domain=cloudflare.com; Expires=Tue, 20 Oct 2026 22:50:16 GMT
report-to {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=FZJiHxPVa31z7Glf1I%2BbdALorDoJAxyJ6ZsedbLSjQQP%2Bus5mphMTkVKfjk%2BjsQT%2BU%2BqTcOYo1Y8S4OG3QMCvy9ayoZFdanPvo%2FVzwvMp%2FZnWfNfwotiwSmrx5m3vDkn"}]}
nel {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
server cloudflare
priority u=3,i=?0
cf-ray a4db68ac9b605a48-FRA
alt-svc h3=":443"; ma=86400
server-timing cfExtPri