Learn PREACT with Real Code Examples

Preact allows developers to create UI components using a syntax similar to React.

It offers a virtual DOM for efficient updates while keeping the library extremely small.

Preact is designed for performance-critical applications and low-resource environments.

JSX support

Functional and class components

Hooks API

Virtual DOM diffing

Context API for state management

Functional and class components

JSX templating

Virtual DOM updates

Hooks for state and effects

Component composition

src/components - reusable components

src/pages - app pages

src/index.js - entry point

package.json - dependencies

vite.config.js - optional bundler config

Create Preact components (functional/class)

Use props and state for dynamic UI

Apply hooks (useState, useEffect, useRef)

Compose components hierarchically

Render root component using `render()`

Beginner: single-page components

Intermediate: multi-component apps

Advanced: PWA with routing & state

Expert: React migration projects

Community: optimizing bundle size & performance

Smaller and faster than React

Easier migration from React than Vue or Angular

Better performance for low-resource apps

Smaller ecosystem than React

Compatible with React libraries via preact/compat

2015 – Initial release

2016 – Hooks & functional components introduced

2019 – Preact X (major rewrite with hooks & context)

2021 – TypeScript and ecosystem improvements

2025 – Continued optimizations and ecosystem growth

Virtual DOM: Efficient UI diffing mechanism

preact/compat: React compatibility layer

Functional Component: Stateless or hook-based component

Class Component: Stateful component with lifecycle methods

JSX: JavaScript syntax for HTML templates