Preact is a fast, small JavaScript library for building user interfaces. It’s often described as a “3KB alternative to React” because it provides the same modern API (components, hooks, virtual DOM) with a much smaller bundle size.

Preact is not a fork of React—it’s an independent implementation that stays compatible with React’s core ideas. You can think of it as “React, but tiny”: same mental model, same ecosystem (e.g. you can use many React libraries), with a focus on performance and size.