Preact is a fast 3kB alternative to React, with the same modern API. It lets developers build high-performance user interfaces using the familiar component model, JSX, and hooks that React users already know, while shipping dramatically less JavaScript to the browser. Unlike heavier alternatives, it prioritizes the essentials that most applications actually use, which keeps the learning surface small and the bundle cost predictable for teams of any size.
At its core, Preact uses a thin virtual DOM that is optimized for both size and speed, enabling it to update the screen efficiently even on low-powered devices. The library implements the standard React component lifecycle and context API, so most React code runs with little or no modification. This makes Preact a natural fit for embedding interactive widgets into larger sites and for progressively enhancing server-rendered pages without a heavy client runtime.
A key feature is the option to use Preact with the React compatibility layer, allowing teams to gradually adopt it in existing projects or share components across codebases. It also ships first-class support for server-side rendering, hydration, and modern build tooling. Developers can lazy-load routes and components to keep initial payloads tiny, which is especially valuable for content sites and marketing pages where speed directly affects engagement.
Preact is particularly popular for performance-critical applications and progressive web apps, where every kilobyte matters. Companies use it to improve load times, reduce bundle size, and deliver snappier interactions, especially on mobile networks. Its compact size also reduces parse and execution time on the client, contributing to better Core Web Vitals and a smoother perceived performance for end users in real-world conditions.
Backed by an active open-source community and a lightweight, focused design philosophy, Preact remains a pragmatic choice for developers who want React ergonomics without its weight. Its small footprint, clear documentation, and broad ecosystem make it suitable for everything from small widgets to full applications. The project is MIT licensed and backed by a foundation, giving teams confidence in its long-term governance and the stability of the APIs they build on.
