HTTP/2 and HTTP/3 explained

published on 2024/03/13


In 2015, after many years of observation and studies on the performance of the Internet, the HTTP/2 was proposed and created, based on Google's SPDY.

Among its differences, were the multiplexing of many messages in a single TCP packet; binary format of the messages; and HPACK compression for headers.

In HTTP/1.1, two requests cannot ride together the same TCP connection - it is necessary that the first one ends for the subsequent to begin. This is called head-of-line blocking. In the diagram below, request 2 cannot be sent until response 1 arrives, considering that only one TCP connection is used.