Lesson 7 / 25

HTTP/2 and HTTP/3

Modern protocols that improve performance through multiplexing, header compression, and faster handshakes.

HTTP/2 multiplexing

HTTP/2 sends multiple requests over one connection simultaneously. No need to bundle assets or domain sharding. Header compression (HPACK) reduces overhead. Automatic prioritization of critical resources.

HTTP/3 and QUIC

HTTP/3 uses QUIC (UDP-based) instead of TCP. Faster connection establishment (0-RTT resumption), better loss recovery. Particularly beneficial for high-latency and mobile networks.

Protocol adoption timeline

HTTP/1.1 (obsolete), HTTP/2 (96% browser support), HTTP/3 (growing but not universal). Check your server/CDN support. Most modern CDNs support both HTTP/2 and HTTP/3.

Quick check

Quick check: What is a key advantage of HTTP/3?

  • Uses UDP instead of TCP for faster handshake
  • Smaller file sizes
  • No compression needed
Answer