topic
Verified 2026-09-18HTTP/3 and QUIC
HTTP/3 maps HTTP semantics onto QUIC streams rather than TCP.
HTTP/3 provides independent stream loss recovery and uses QUIC/TLS negotiation. Applications should preserve HTTP semantics while handling connection migration, 0-RTT replay risk, and version fallback.
httphttp3quicperformancesecurity
Reference (http)
Alt-Svc: h3=":443"; ma=86400 HTTP/3 ALPN: h3
HTTP/3 provides independent stream loss recovery and uses QUIC/TLS negotiation. Applications should preserve HTTP semantics while handling connection migration, 0-RTT replay risk, and version fallback.
Common mistakes
- Assuming HTTP/3 makes requests replay-safe or treating Alt-Svc as a redirect without validating the alternative service.