---
title: 'HTTP/1 -> HTTP/2 -> HTTP/3'
description: 'Explore the evolution of HTTP: from HTTP/1 to the latest HTTP/3.'
image: 'https://assets.bytebytego.com/diagrams/0101-http-1-http-2-http-3.png'
createdAt: '2024-03-02'
draft: false
categories:
  - api-web-development
tags:
  - HTTP
  - Protocols
---

![](https://assets.bytebytego.com/diagrams/0101-http-1-http-2-http-3.png)

HTTP 1 started in 1996 followed by HTTP 1.1 the very next year. In 2015, HTTP 2 came about and in 2019 we got HTTP 3.

With each iteration, the protocol has evolved in new and interesting ways.

*   **HTTP 1** (and its sub-versions) introduced features like persistent connections, pipelining, and the concept of headers. The protocol was built on top of TCP and provided a reliable way of communication over the World Wide Web. It is still used despite being over 25 years old.
*   **HTTP 2** brought new features such as multiplexing, stream prioritization, server push, and HPACK compression. However, it still used TCP as the underlying protocol.
*   **HTTP 3** uses Google’s QUIC, which is built on top of UDP. In other words, HTTP 3 has moved away from TCP.