HTTP/3 is the latest version of the Hypertext Transfer Protocol. Unlike HTTP/1.1 and HTTP/2, which rely on TCP, HTTP/3 is built on QUIC, a transport layer protocol developed by Google that runs over UDP.

Solving Head-of-Line Blocking

In HTTP/2 over TCP, if one packet is lost, the entire TCP connection halts until it is retransmitted (Head-of-Line Blocking). QUIC multiplexes streams over UDP; if a packet for Stream A is lost, Stream B can continue unimpeded.