HTTP/2 and HTTP/3

HTTP/2 added multiplexing, HTTP/3 brings QUIC over UDP for lower latency.

HTTP/2¶

• Multiplexing — multiple requests over a single TCP connection
• Header compression (HPACK)
• Server Push
• Binary protocol

server { listen 443 ssl http2; } curl -I –http2 https://example.com

HTTP/3¶

• QUIC — UDP instead of TCP
• 0-RTT reconnect
• No head-of-line blocking
• TLS 1.3 built-in

server { listen 443 quic reuseport; listen 443 ssl http2; add_header Alt-Svc ‘h3=”:443”’; }

When to Use¶

• HTTP/2 — deploy now, supported everywhere
• HTTP/3 — mobile users, global audience

HTTP/2 Today, HTTP/3 Tomorrow¶

HTTP/2 is a must-have. HTTP/3 for mobile networks.