HTTP/3
The third major version of HTTP, built on QUIC instead of TCP, offering faster connection setup and better recovery from packet loss.
HTTP/3 is the latest version of the HTTP protocol, standardised in 2022. Unlike HTTP/1.1 and HTTP/2 which run on TCP, HTTP/3 runs on QUIC, a UDP-based transport that integrates TLS 1.3 directly into the handshake. The practical wins: 1-RTT (or 0-RTT for repeat visits) connection setup, no head-of-line blocking when a packet is lost, and seamless connection migration when a client's IP changes (for example, switching from Wi-Fi to cellular). Modern browsers and CDNs negotiate HTTP/3 via ALPN, falling back to HTTP/2 if QUIC traffic is blocked.