UnoCSS

The instant on-demand Atomic CSS engine.

💡 I highly recommend reading this blog post -
Reimagine Atomic CSS
for the story behind

📚 Documentation |
🧑‍💻 Interactive Docs |
🤹‍♂️ Playground |
🎓 Tutorial

Features

Inspired by Windi CSS, Tailwind CSS, and Twind, but:

- Fully customizable - no core utilities. All functionalities are provided via presets.
- No parsing, no AST, no scanning, it's INSTANT (5x faster than Windi CSS or Tailwind JIT).
- ~6kb min+brotli - zero deps and browser friendly.
- Shortcuts - aliasing utilities, dynamically.
- Attributify mode - group utilities in attributes.
- Pure CSS Icons - use any icon as a single class.
- Variant Groups - shorthand for group utils with common prefixes.
- CSS Directives - reuse utils in CSS with @apply directive.
- Compilation mode - synthesizes multiple classes into one at build time.
- Inspector - inspect and debug interactively.
- CSS-in-JS Runtime build - use UnoCSS with one line of CDN import.
- VS Code extension
- Code-splitting for CSS - ships minimal CSS for MPA.