UnoCSS

The instant on-demand atomic CSS engine

Instant on-demand atomic CSS engine. Highly customizable with Tailwind/Windi/Bootstrap presets. Extremely fast with Vite integration.

16K

GitHub Stars

native

TypeScript

medium

Learning Curve

4.5

DX Score

Visit Website → Documentation GitHub

Pricing

Model

free

Free Tier

MIT licensed, fully open source

Features

✓ Instant on-demand generation
✓ Fully customizable with presets
✓ Tailwind/Windi CSS compatible
✓ Attributify mode
✓ Pure CSS icons
✓ CSS directives
✓ Variant groups
✓ Shortcuts support

Pros

+ Extremely fast (200x faster than Tailwind JIT)
+ Highly flexible and customizable
+ Multiple preset support
+ Smaller runtime footprint
+ First-class Vite integration

Cons

- Smaller community than Tailwind
- Less third-party resources
- May require preset configuration
- Newer, less battle-tested

Best For

startup indie hacker

Alternatives

Tailwind CSS

css utility-first atomic-css vite performance