Preact is a fast 3kB alternative to React, boasting the same modern ES6 API. It focuses on providing the core value of React in a much smaller size. Developers can easily transition to Preact to enhance web application performance, especially on resource-constrained devices. Preact emphasizes speed and efficiency, making it ideal for projects prioritizing a lightweight and performant user interface library. It fully supports the component model while adhering closely to browser standards.