Preact — Fast 3kB React Alternative with Same Modern API

What Preact Does

• Same API as React — components, hooks, context, suspense
• Virtual DOM — efficient diffing, smaller runtime
• preact/compat — React drop-in replacement
• preact/signals — fine-grained reactive primitives
• preact/hooks — same hooks API as React
• SSR — preact-render-to-string
• Islands architecture — Astro + Preact is a common combo

Architecture

Core is a minimal virtual DOM differ. Components can be functional or class. No SyntheticEvent system (uses native events). Smaller runtime overhead means faster boot and smaller bundles.

Self-Hosting

Client library. Pairs with Vite, Astro, Next.js (via preact adapter).

Key Features

• 3KB gzipped runtime
• React-compatible API
• Hooks, Context, Suspense
• React compat mode
• Signals (fine-grained reactivity)
• SSR support
• No legacy baggage
• Tiny JSX runtime

Comparison

FAQ

Q: Is it fully compatible with React? A: With preact/compat, most React libraries work directly. Some libraries that rely on React internals (React Native, certain versions of React Hook Form) may not be compatible.

Q: Is it really faster than React? A: Startup and initial render are faster (small runtime). The diff performance gap narrows in large applications.

Q: When should I use Preact? A: Scenarios where bundle size matters: landing pages, islands architecture (Astro), embedded widgets, and PWAs.

Sources & Credits

• Docs: https://preactjs.com
• GitHub: https://github.com/preactjs/preact
• License: MIT