Connection Establishment

A visualization of how many round trips (RTT) it takes to establish a secure connection and send the first byte of data.

50ms

Why HTTP/3 is faster:

  • HTTP/1.1 & 2: TCP Handshake (1 RTT) + TLS Handshake (1-2 RTT) = 2-3 RTTs before data.
  • HTTP/3 (QUIC): Cryptographic and transport handshakes are combined taking only 1 RTT.
  • 0-RTT: Returning clients can send data in the very first packet.

HTTP/1.1 + TLS 1.2

0ms
Client
Server

HTTP/2 + TLS 1.3

0ms
Client
Server

HTTP/3 (QUIC)

0ms
Client
Server