UnoCSS is an instant atomic CSS engine designed to be flexible and extensible. The core is un-opinionated - all CSS utilities are provided via presets. It's a superset of Tailwind CSS, so you can reuse your Tailwind knowledge for basic syntax usage.
Important: Before writing UnoCSS code, agents should check for uno.config.* or unocss.config.* files in the project root to understand what presets, rules, and shortcuts are available. If the project setup is unclear, avoid using attributify mode and other advanced features - stick to basic class usage.
The skill is based on UnoCSS 66.x, generated at 2026-01-28.
Core
| Topic |
Description |
Reference |
| Configuration |
Config file setup and all configuration options |
core-config |
| Rules |
Static and dynamic rules for generating CSS utilities |
core-rules |
| Shortcuts |
Combine multiple rules into single shorthands |
core-shortcuts |
| Theme |
Theming system for colors, breakpoints, and design tokens |
core-theme |
| Variants |
Apply variations like hover:, dark:, responsive to rules |
core-variants |
| Extracting |
How UnoCSS extracts utilities from source code |
core-extracting |
| Safelist & Blocklist |
Force include or exclude specific utilities |
core-safelist |
| Layers & Preflights |
CSS layer ordering and raw CSS injection |
core-layers |
Presets
Main Presets
| Topic |
Description |
Reference |
| Preset Wind3 |
Tailwind CSS v3 / Windi CSS compatible preset (most common) |
preset-wind3 |
| Preset Wind4 |
Tailwind CSS v4 compatible preset with modern CSS features |
preset-wind4 |
| Preset Mini |
Minimal preset with essential utilities for custom builds |
preset-mini |
Feature Presets
| Topic |
Description |
Reference |
| Preset Icons |
Pure CSS icons using Iconify with any icon set |
preset-icons |
| Preset Attributify |
Group utilities in HTML attributes instead of class |
preset-attributify |
| Preset Typography |
Prose classes for typographic defaults |
preset-typography |
| Preset Web Fonts |
Easy Google Fonts and other web fonts integration |
preset-web-fonts |
| Preset Tagify |
Use utilities as HTML tag names |
preset-tagify |
| Preset Rem to Px |
Convert rem units to px for utilities |
preset-rem-to-px |
Transformers
| Topic |
Description |
Reference |
| Variant Group |
Shorthand for grouping utilities with common prefixes |
transformer-variant-group |
| Directives |
CSS directives: @apply, @screen, theme(), icon() |
transformer-directives |
| Compile Class |
Compile multiple classes into one hashed class |
transformer-compile-class |
| Attributify JSX |
Support valueless attributify in JSX/TSX |
transformer-attributify-jsx |
Integrations
| Topic |
Description |
Reference |
| Vite Integration |
Setting up UnoCSS with Vite and framework-specific tips |
integrations-vite |
| Nuxt Integration |
UnoCSS module for Nuxt applications |
integrations-nuxt |
---
name: unocss
description: Configure and use UnoCSS, an instant atomic CSS engine with presets, rules, shortcuts, and integrations for Vite and Nuxt.
---
UnoCSS is an instant atomic CSS engine designed to be flexible and extensible. The core is un-opinionated - all CSS utilities are provided via presets. It's a superset of Tailwind CSS, so you can reuse your Tailwind knowledge for basic syntax usage.
**Important:** Before writing UnoCSS code, agents should check for `uno.config.*` or `unocss.config.*` files in the project root to understand what presets, rules, and shortcuts are available. If the project setup is unclear, avoid using attributify mode and other advanced features - stick to basic `class` usage.
> The skill is based on UnoCSS 66.x, generated at 2026-01-28.
## Core
| Topic | Description | Reference |
|-------|-------------|-----------|
| Configuration | Config file setup and all configuration options | [core-config](references/core-config.md) |
| Rules | Static and dynamic rules for generating CSS utilities | [core-rules](references/core-rules.md) |
| Shortcuts | Combine multiple rules into single shorthands | [core-shortcuts](references/core-shortcuts.md) |
| Theme | Theming system for colors, breakpoints, and design tokens | [core-theme](references/core-theme.md) |
| Variants | Apply variations like hover:, dark:, responsive to rules | [core-variants](references/core-variants.md) |
| Extracting | How UnoCSS extracts utilities from source code | [core-extracting](references/core-extracting.md) |
| Safelist & Blocklist | Force include or exclude specific utilities | [core-safelist](references/core-safelist.md) |
| Layers & Preflights | CSS layer ordering and raw CSS injection | [core-layers](references/core-layers.md) |
## Presets
### Main Presets
| Topic | Description | Reference |
|-------|-------------|-----------|
| Preset Wind3 | Tailwind CSS v3 / Windi CSS compatible preset (most common) | [preset-wind3](references/preset-wind3.md) |
| Preset Wind4 | Tailwind CSS v4 compatible preset with modern CSS features | [preset-wind4](references/preset-wind4.md) |
| Preset Mini | Minimal preset with essential utilities for custom builds | [preset-mini](references/preset-mini.md) |
### Feature Presets
| Topic | Description | Reference |
|-------|-------------|-----------|
| Preset Icons | Pure CSS icons using Iconify with any icon set | [preset-icons](references/preset-icons.md) |
| Preset Attributify | Group utilities in HTML attributes instead of class | [preset-attributify](references/preset-attributify.md) |
| Preset Typography | Prose classes for typographic defaults | [preset-typography](references/preset-typography.md) |
| Preset Web Fonts | Easy Google Fonts and other web fonts integration | [preset-web-fonts](references/preset-web-fonts.md) |
| Preset Tagify | Use utilities as HTML tag names | [preset-tagify](references/preset-tagify.md) |
| Preset Rem to Px | Convert rem units to px for utilities | [preset-rem-to-px](references/preset-rem-to-px.md) |
## Transformers
| Topic | Description | Reference |
|-------|-------------|-----------|
| Variant Group | Shorthand for grouping utilities with common prefixes | [transformer-variant-group](references/transformer-variant-group.md) |
| Directives | CSS directives: @apply, @screen, theme(), icon() | [transformer-directives](references/transformer-directives.md) |
| Compile Class | Compile multiple classes into one hashed class | [transformer-compile-class](references/transformer-compile-class.md) |
| Attributify JSX | Support valueless attributify in JSX/TSX | [transformer-attributify-jsx](references/transformer-attributify-jsx.md) |
## Integrations
| Topic | Description | Reference |
|-------|-------------|-----------|
| Vite Integration | Setting up UnoCSS with Vite and framework-specific tips | [integrations-vite](references/integrations-vite.md) |
| Nuxt Integration | UnoCSS module for Nuxt applications | [integrations-nuxt](references/integrations-nuxt.md) |