Uniwind — Complete Reference
Uniwind 1.5.0+ / Tailwind CSS v4 / React Native 0.81+ / Expo SDK 54+
If user has lower version, recommend updating to 1.5.0+ for best experience.
Uniwind brings Tailwind CSS v4 to React Native. All core React Native components support the className prop out of the box. Styles are compiled at build time — no runtime overhead.
Critical Rules
- Tailwind v4 only — Use
@import 'tailwindcss'not@tailwind base. Tailwind v3 is not supported. - Never construct classNames dynamically — Tailwind scans at build time.
bg-${color}-500will NOT work. Use complete string literals, mapping objects, or ternaries. - Never use
cssInteroporremapProps— Those are NativeWind APIs. Uniwind does not override global components. - No
tailwind.config.js— All config goes inglobal.cssvia@themeand@layer theme. - No ThemeProvider required — Use
Uniwind.setTheme()directly. withUniwindConfigmust be the outermost Metro config wrapper.- NEVER wrap
react-nativeorreact-native-reanimatedcomponents withwithUniwind—View,Text,Pressable,Image,TextInput,ScrollView,FlatList,Switch,Modal,Animated.View,Animated.Text, etc. already have fullclassNamesupport built in. Wrapping them withwithUniwindwill break behavior. Only usewithUniwindfor third-party components (e.g.,expo-image,expo-blur,moti). - Font families: single font only — React Native doesn't support fallbacks. Use
--font-sans: 'Roboto-Regular'not'Roboto', sans-serif. - All theme variants must define the same set of CSS variables — If
lightdefines--color-primary, thendarkand every custom theme must too. Mismatched variables cause runtime errors. accent-prefix is REQUIRED for non-style color props — This is crucial. Props likecolor(Button, ActivityIndicator),tintColor(Image),thumbColor(Switch),placeholderTextColor(TextInput) are NOT part of thestyleobject. You MUST use the corresponding{propName}ClassNameprop withaccent-prefixed classes. Example:<ActivityIndicator colorClassName="accent-blue-500" />NOT<ActivityIndicator className="text-blue-500" />. Regular Tailwind color classes (liketext-blue-500) only work onclassName(which maps tostyle). For non-style color props, always useaccent-.- rem default is 16px — NativeWind used 14px. Set
polyfills: { rem: 14 }in metro config if migrating. cssEntryFilemust be a relative path string — Use'./global.css'notpath.resolve(__dirname, 'global.css').- Deduplicate with
cn()when mixing custom CSS classes and Tailwind — Uniwind does NOT auto-deduplicate. If a custom CSS class (.card { padding: 16px }) and a Tailwind utility (p-6) set the same property, both apply with unpredictable results. Always wrap withcn('card', 'p-6')when there's overlap.
Setup
Installation
# or other package manager
bun install uniwind tailwindcss
Requires Tailwind CSS v4+.
global.css
Create a CSS entry file:
@import 'tailwindcss';
@import 'uniwind';
Import in your App component (e.g., App.tsx or app/_layout.tsx), NOT in index.ts/index.js — importing there breaks hot reload:
// app/_layout.tsx or App.tsx
import './global.css';
The directory containing global.css is the app root — Tailwind scans for classNames starting from this directory.
Metro Configuration
const { getDefaultConfig } = require('expo/metro-config');
// Bare RN: const { getDefaultConfig } = require('@react-native/metro-config');
const { withUniwindConfig } = require('uniwind/metro');
const config = getDefaultConfig(__dirname);
// withUniwindConfig MUST be the OUTERMOST wrapper
module.exports = withUniwindConfig(config, {
cssEntryFile: './global.css', // Required — relative path from project root
polyfills: { rem: 16 }, // Optional — base rem value (default 16)
extraThemes: ['ocean', 'sunset'], // Optional — custom themes beyond light/dark
dtsFile: './uniwind-types.d.ts', // Optional — TypeScript types output path
debug: true, // Optional — log unsupported CSS in dev
isTV: false, // Optional — enable TV platform support
});
For most flows, keep defaults, only provide cssEntryFile.
Wrapper order — Uniwind must wrap everything else:
// CORRECT
module.exports = withUniwindConfig(withOtherConfig(config, opts), { cssEntryFile: './global.css' });
// WRONG — Uniwind is NOT outermost
module.exports = withOtherConfig(withUniwindConfig(config, { cssEntryFile: './global.css' }), opts);
Vite Configuration (v1.2.0+)
If user has storybook setup, add extra vite config:
import tailwindcss from '@tailwindcss/vite';
import { uniwind } from 'uniwind/vite';
import { defineConfig } from 'vite';
export default defineConfig({
plugins: [
tailwindcss(),
uniwind({
cssEntryFile: './src/global.css',
dtsFile: './src/uniwind-types.d.ts',
}),
],
});
TypeScript
Uniwind auto-generates a .d.ts file (default: ./uniwind-types.d.ts) after running Metro. Place it in src/ or app/ for auto-inclusion, or add to tsconfig.json:
{ "include": ["./uniwind-types.d.ts"] }
If user has some typescript errors related to classNames, just run metro server to build the d.ts file.
Expo Router Placement
project/
├── app/_layout.tsx ← import '../global.css' here
├── components/
├── global.css ← project root (best location)
└── metro.config.js ← cssEntryFile: './global.css'
If global.css is in app/ dir, add @source for sibling directories:
@import 'tailwindcss';
@import 'uniwind';
@source '../components';
Tailwind IntelliSense (VS Code / Cursor / Windsurf)
{
"tailwindCSS.classAttributes": [
"class", "className", "headerClassName",
"contentContainerClassName", "columnWrapperClassName",
"endFillColorClassName", "imageClassName", "tintColorClassName",
"ios_backgroundColorClassName", "thumbColorClassName",
"trackColorOnClassName", "trackColorOffClassName",
"selectionColorClassName", "cursorColorClassName",
"underlineColorAndroidClassName", "placeholderTextColorClassName",
"selectionHandleColorClassName", "colorsClassName",
"progressBackgroundColorClassName", "titleColorClassName",
"underlayColorClassName", "colorClassName",
"backdropColorClassName", "backgroundColorClassName",
"statusBarBackgroundColorClassName", "drawerBackgroundColorClassName",
"ListFooterComponentClassName", "ListHeaderComponentClassName"
],
"tailwindCSS.classFunctions": ["useResolveClassNames"]
}
Monorepo Support
Add @source directives in global.css for packages outside the CSS entry file's directory:
@import 'tailwindcss';
@import 'uniwind';
@source "../../packages/ui/src";
@source "../../packages/shared/src";
Also needed for node_modules packages that contain Uniwind classes (e.g., shared UI libraries).
Component Bindings
All core React Native components support className out of the box. Some have additional className props for sub-styles (like contentContainerClassName) and non-style color props (requiring accent- prefix).
Complete Reference
Legend: Props marked with ⚡ require the accent- prefix. Props in parentheses are platform-specific.
View
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
Text
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
selectionColorClassName | selectionColor | ⚡ accent- |
Pressable
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
Supports active:, disabled:, focus: state selectors.
Image
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
tintColorClassName | tintColor | ⚡ accent- |
TextInput
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
cursorColorClassName | cursorColor | ⚡ accent- |
selectionColorClassName | selectionColor | ⚡ accent- |
placeholderTextColorClassName | placeholderTextColor | ⚡ accent- |
selectionHandleColorClassName | selectionHandleColor | ⚡ accent- |
underlineColorAndroidClassName | underlineColorAndroid (Android) | ⚡ accent- |
Supports focus:, active:, disabled: state selectors.
ScrollView
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
contentContainerClassName | contentContainerStyle | — |
endFillColorClassName | endFillColor | ⚡ accent- |
FlatList
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
contentContainerClassName | contentContainerStyle | — |
columnWrapperClassName | columnWrapperStyle | — |
ListHeaderComponentClassName | ListHeaderComponentStyle | — |
ListFooterComponentClassName | ListFooterComponentStyle | — |
endFillColorClassName | endFillColor | ⚡ accent- |
SectionList
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
contentContainerClassName | contentContainerStyle | — |
ListHeaderComponentClassName | ListHeaderComponentStyle | — |
ListFooterComponentClassName | ListFooterComponentStyle | — |
endFillColorClassName | endFillColor | ⚡ accent- |
VirtualizedList
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
contentContainerClassName | contentContainerStyle | — |
ListHeaderComponentClassName | ListHeaderComponentStyle | — |
ListFooterComponentClassName | ListFooterComponentStyle | — |
endFillColorClassName | endFillColor | ⚡ accent- |
Switch
| Prop | Maps to | Prefix |
|---|---|---|
thumbColorClassName | thumbColor | ⚡ accent- |
trackColorOnClassName | trackColor.true (on) | ⚡ accent- |
trackColorOffClassName | trackColor.false (off) | ⚡ accent- |
ios_backgroundColorClassName | ios_backgroundColor (iOS) | ⚡ accent- |
Note: Switch does NOT support className (className?: never in types). Use only the color-specific className props above. Supports disabled: state selector.
ActivityIndicator
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
colorClassName | color | ⚡ accent- |
Button
| Prop | Maps to | Prefix |
|---|---|---|
colorClassName | color | ⚡ accent- |
Note: Button does not support className (no style prop on RN Button).
Modal
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
backdropColorClassName | backdropColor | ⚡ accent- |
RefreshControl
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
colorsClassName | colors (Android) | ⚡ accent- |
tintColorClassName | tintColor (iOS) | ⚡ accent- |
titleColorClassName | titleColor (iOS) | ⚡ accent- |
progressBackgroundColorClassName | progressBackgroundColor (Android) | ⚡ accent- |
ImageBackground
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
imageClassName | imageStyle | — |
tintColorClassName | tintColor | ⚡ accent- |
SafeAreaView
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
KeyboardAvoidingView
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
contentContainerClassName | contentContainerStyle | — |
InputAccessoryView
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
backgroundColorClassName | backgroundColor | ⚡ accent- |
TouchableHighlight
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
underlayColorClassName | underlayColor | ⚡ accent- |
Supports active:, disabled: state selectors.
TouchableOpacity
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
Supports active:, disabled: state selectors.
TouchableNativeFeedback
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
Supports active:, disabled: state selectors.
TouchableWithoutFeedback
| Prop | Maps to | Prefix |
|---|---|---|
className | style | — |
Supports active:, disabled: state selectors.
Usage Examples
import { View, Text, Pressable, TextInput, ScrollView, FlatList, Switch, Image, ActivityIndicator, Modal, RefreshControl, Button } from 'react-native';
// View — basic layout
<View className="flex-1 bg-background p-4">
<Text className="text-foreground text-lg font-bold">Title</Text>
</View>
// Pressable — with press/focus states
<Pressable className="bg-primary px-6 py-3 rounded-lg active:opacity-80 active:bg-primary/90 focus:ring-2">
<Text className="text-white text-center font-semibold">Press Me</Text>
</Pressable>
// TextInput — with focus state and accent- color props
<TextInput
className="border border-border rounded-lg px-4 py-2 text-base text-foreground focus:border-primary"
placeholderTextColorClassName="accent-muted"
selectionColorClassName="accent-primary"
cursorColorClassName="accent-primary"
selectionHandleColorClassName="accent-primary"
underlineColorAndroidClassName="accent-transparent"
placeholder="Enter text..."
/>
// ScrollView — with content container
<ScrollView className="flex-1" contentContainerClassName="p-4 gap-4">
{/* content */}
</ScrollView>
// FlatList — with all sub-style props
<FlatList
className="flex-1"
contentContainerClassName="p-4 gap-3"
columnWrapperClassName="gap-3"
ListHeaderComponentClassName="pb-4"
ListFooterComponentClassName="pt-4"
endFillColorClassName="accent-gray-100"
numColumns={2}
data={items}
renderItem={({ item }) => <ItemCard item={item} />}
/>
// Switch — no className support, use color-specific props only
<Switch
thumbColorClassName="accent-white"
trackColorOnClassName="accent-primary"
trackColorOffClassName="accent-gray-300 dark:accent-gray-700"
ios_backgroundColorClassName="accent-gray-200"
/>
// Image — tint color
<Image className="w-6 h-6" tintColorClassName="accent-primary" source={icon} />
// ActivityIndicator
<ActivityIndicator className="m-4" colorClassName="accent-primary" size="large" />
// Button — only colorClassName (no className)
<Button colorClassName="accent-primary" title="Submit" onPress={handleSubmit} />
// Modal — backdrop color
<Modal className="flex-1" backdropColorClassName="accent-black/50">
{/* content */}
</Modal>
// RefreshControl — platform-specific color props
<RefreshControl
className="p-4"
tintColorClassName="accent-primary"
titleColorClassName="accent-gray-500"
colorsClassName="accent-primary"
progressBackgroundColorClassName="accent-white dark:accent-gray-800"
/>
// ImageBackground — separate image styling
<ImageBackground
className="flex-1 justify-center items-center"
imageClassName="opacity-50"
tintColorClassName="accent-blue-500"
source={bgImage}
>
<Text className="text-white text-2xl font-bold">Overlay</Text>
</ImageBackground>
// KeyboardAvoidingView
<KeyboardAvoidingView
behavior="padding"
className="flex-1 bg-white"
contentContainerClassName="p-4 justify-end"
>
<TextInput className="border border-gray-300 rounded-lg p-3" placeholder="Type..." />
</KeyboardAvoidingView>
// InputAccessoryView
<InputAccessoryView
className="p-4 border-t border-gray-300"
backgroundColorClassName="accent-white dark:accent-gray-800"
>
<Button title="Done" onPress={dismissKeyboard} />
</InputAccessoryView>
// TouchableHighlight — underlay color
<TouchableHighlight
className="bg-blue-500 px-6 py-3 rounded-lg"
underlayColorClassName="accent-blue-600 dark:accent-blue-700"
onPress={handlePress}
>
<Text className="text-white font-semibold">Press Me</Text>
</TouchableHighlight>
The accent- Prefix Pattern
React Native components have props like color, tintColor, thumbColor that are NOT part of the style object. To set these via Tailwind classes, use the accent- prefix with the corresponding {propName}ClassName prop:
// color prop → colorClassName with accent- prefix
<ActivityIndicator colorClassName="accent-blue-500 dark:accent-blue-400" />
<Button colorClassName="accent-primary" title="Submit" />
// tintColor prop → tintColorClassName
<Image className="w-6 h-6" tintColorClassName="accent-red-500" source={icon} />
// thumbColor → thumbColorClassName
<Switch thumbColorClassName="accent-white" trackColorOnClassName="accent-primary" />
// placeholderTextColor → placeholderTextColorClassName
<TextInput placeholderTextColorClassName="accent-gray-400 dark:accent-gray-600" />
CRITICAL Rule: className maps to the style prop — it handles layout, typography, backgrounds, borders, etc. But React Native has many color props that live OUTSIDE of style (like color, tintColor, thumbColor, placeholderTextColor). These require a separate {propName}ClassName prop with the accent- prefix. Without accent-, the class resolves to a style object — but these props expect a plain color string.
// WRONG — className sets style, but ActivityIndicator's color is NOT a style prop
<ActivityIndicator className="text-blue-500" /> // color will NOT be set
// CORRECT — use the dedicated colorClassName prop with accent- prefix
<ActivityIndicator colorClassName="accent-blue-500" /> // color IS set to #3b82f6
// WRONG — tintColor is not a style prop on Image
<Image className="tint-blue-500" source={icon} /> // won't work
// CORRECT
<Image tintColorClassName="accent-blue-500" source={icon} />
Styling Third-Party Components
withUniwind (Recommended)
Wrap once at module level, use with className everywhere:
import { withUniwind } from 'uniwind';
import { Image as ExpoImage } from 'expo-image';
import { BlurView as RNBlurView } from 'expo-blur';
import { LinearGradient as RNLinearGradient } from 'expo-linear-gradient';
// Module-level wrapping (NEVER inside render functions)
export const Image = withUniwind(ExpoImage);
export const BlurView = withUniwind(RNBlurView);
export const LinearGradient = withUniwind(RNLinearGradient);
withUniwind automatically maps:
style→className{name}Style→{name}ClassName{name}Color→{name}ColorClassName(with accent- prefix)
For custom prop mappings:
const StyledProgressBar = withUniwind(ProgressBar, {
width: {
fromClassName: 'widthClassName',
styleProperty: 'width',
},
});
Usage patterns:
- Used in one file only — define the wrapped component in that same file
- Used across multiple files — wrap once in a shared module (e.g.,
components/styled.ts) and re-export
// components/styled.ts
import { withUniwind } from 'uniwind';
import { Image as ExpoImage } from 'expo-image';
export const Image = withUniwind(ExpoImage);
// Then import everywhere:
import { Image } from '@/components/styled';
NEVER call withUniwind on the same component in multiple files.
CRITICAL: Do NOT use withUniwind on components from react-native or react-native-reanimated. These already have built-in className support:
// WRONG — View already supports className natively
const StyledView = withUniwind(View); // DO NOT DO THIS
const StyledText = withUniwind(Text); // DO NOT DO THIS
const StyledAnimatedView = withUniwind(Animated.View); // DO NOT DO THIS
// CORRECT — only wrap third-party components
const StyledExpoImage = withUniwind(ExpoImage); // expo-image
const StyledBlurView = withUniwind(BlurView); // expo-blur
const StyledMotiView = withUniwind(MotiView); // moti
useResolveClassNames
Converts Tailwind class strings to React Native style objects. Use for one-off cases or components that only accept style:
import { useResolveClassNames } from 'uniwind';
const headerStyle = useResolveClassNames('bg-primary p-4');
const cardStyle = useResolveClassNames('bg-card dark:bg-card rounded-lg shadow-sm');
// React Navigation screen options
<Stack.Navigator screenOptions={{ headerStyle, cardStyle }} />
Comparison
| Feature | withUniwind | useResolveClassNames |
|---|---|---|
| Setup | Once per component | Per usage |
| Performance | Optimized | Slightly slower |
| Best for | Reusable components | One-off, navigation config |
| Syntax | className="..." | style={...} |
Dynamic ClassNames
NEVER do this (Tailwind scans at build time)
// BROKEN — template literal with variable
<View className={`bg-${color}-500`} />
<Text className={`text-${size}`} />
Correct patterns
// Ternary with complete class names
<View className={isActive ? 'bg-primary' : 'bg-muted'} />
// Mapping object
const colorMap = {
primary: 'bg-blue-500 text-white',
danger: 'bg-red-500 text-white',
ghost: 'bg-transparent text-foreground',
};
<Pressable className={colorMap[variant]} />
// Array join for multiple conditions
<View className={[
'p-4 rounded-lg',
isActive && 'bg-primary',
isDisabled && 'opacity-50',
].filter(Boolean).join(' ')} />
tailwind-variants (tv)
For complex component styling with variants and compound variants:
import { tv } from 'tailwind-variants';
const button = tv({
base: 'font-semibold rounded-lg px-4 py-2 items-center justify-center',
variants: {
color: {
primary: 'bg-blue-500 text-white',
secondary: 'bg-gray-500 text-white',
danger: 'bg-red-500 text-white',
ghost: 'bg-transparent text-foreground border border-border',
},
size: {
sm: 'text-sm px-3 py-1.5',
md: 'text-base px-4 py-2',
lg: 'text-lg px-6 py-3',
},
disabled: {
true: 'opacity-50',
},
},
compoundVariants: [
{ color: 'primary', size: 'lg', class: 'bg-blue-600' },
],
defaultVariants: { color: 'primary', size: 'md' },
});
<Pressable className={button({ color: 'primary', size: 'lg' })}>
<Text className="text-white font-semibold">Click</Text>
</Pressable>
cn Utility — Class Deduplication
Uniwind does NOT auto-deduplicate conflicting classNames. This means if the same property appears in multiple classes, both will be applied and the result is unpredictable. This is especially critical when mixing custom CSS classes with Tailwind utilities.
Setup
npm install tailwind-merge clsx
// lib/cn.ts
import { type ClassValue, clsx } from 'clsx';
import { twMerge } from 'tailwind-merge';
export function cn(...inputs: ClassValue[]) {
return twMerge(clsx(inputs));
}
When cn Is Required
- Merging className props — component accepts external className that may conflict:
import { cn } from '@/lib/cn';
<View className={cn('p-4 bg-white', props.className)} />
<Text className={cn('text-base', isActive && 'text-primary', disabled && 'opacity-50')} />
- CRITICAL: Mixing custom CSS classes with Tailwind utilities — if your custom CSS class sets a property that a Tailwind utility also sets, you MUST use
cn()to deduplicate:
/* global.css */
.card {
background-color: white;
border-radius: 12px;
padding: 16px;
}
// WRONG — both .card (padding: 16px) and p-6 (padding: 24px) apply, result is unpredictable
<View className="card p-6" />
// CORRECT — cn deduplicates, p-6 wins over .card's padding
<View className={cn('card', 'p-6')} />
- tv() output combined with extra classes — tv already handles its own variants, but if you add more classes on top:
<Pressable className={cn(button({ color: 'primary' }), props.className)} />
When cn Is NOT Needed
- Static className with no conflicts:
<View className="flex-1 p-4 bg-white" /> - Single custom CSS class with no overlapping Tailwind:
<View className="card-shadow mt-4" />(if card-shadow only sets box-shadow which no Tailwind class also sets)
Theming
Quick Setup (dark: prefix)
Works immediately — no configuration needed:
<View className="bg-white dark:bg-gray-900">
<Text className="text-black dark:text-white">Themed</Text>
</View>
Best for small apps and prototyping. Does not scale to custom themes.
Scalable Setup (CSS Variables)
Define in global.css, use everywhere without dark: prefix:
@layer theme {
:root {
@variant light {
--color-background: #ffffff;
--color-foreground: #111827;
--color-foreground-secondary: #6b7280;
--color-card: #ffffff;
--color-border: #e5e7eb;
--color-muted: #9ca3af;
--color-primary: #3b82f6;
--color-danger: #ef4444;
--color-success: #10b981;
}
@variant dark {
--color-background: #000000;
--color-foreground: #ffffff;
--color-foreground-secondary: #9ca3af;
--color-card: #1f2937;
--color-border: #374151;
--color-muted: #6b7280;
--color-primary: #3b82f6;
--color-danger: #ef4444;
--color-success: #10b981;
}
}
}
// Auto-adapts to current theme — no dark: prefix needed
<View className="bg-card border border-border p-4 rounded-lg">
<Text className="text-foreground text-lg font-bold">Title</Text>
<Text className="text-muted mt-2">Subtitle</Text>
</View>
Variable naming: --color-background → bg-background, text-background.
Prefer CSS variables over explicit dark: variants — they're cleaner, maintain easier, and work with custom themes automatically.
Custom Themes
Step 1 — Define in global.css:
@layer theme {
:root {
@variant light { /* ... */ }
@variant dark { /* ... */ }
@variant ocean {
--color-background: #0c4a6e;
--color-foreground: #e0f2fe;
--color-primary: #06b6d4;
--color-card: #0e7490;
--color-border: #155e75;
/* Must define ALL the same variables as light/dark */
}
}
}
Step 2 — Register in metro.config.js (exclude light/dark — they're automatic):
module.exports = withUniwindConfig(config, {
cssEntryFile: './global.css',
extraThemes: ['ocean'],
});
Restart Metro after adding themes.
Step 3 — Use:
Uniwind.setTheme('ocean');
Theme API
import { Uniwind, useUniwind } from 'uniwind';
// Imperative (no re-render)
Uniwind.setTheme('dark'); // Force dark
Uniwind.setTheme('light'); // Force light
Uniwind.setTheme('system'); // Follow device (re-enables adaptive themes)
Uniwind.setTheme('ocean'); // Custom theme (must be in extraThemes)
Uniwind.currentTheme; // Current theme name
Uniwind.hasAdaptiveThemes; // true if following system
// Reactive hook (re-renders on change)
const { theme, hasAdaptiveThemes } = useUniwind();
Uniwind.setTheme('light') / setTheme('dark') also calls Appearance.setColorScheme to sync native components (Alert, Modal, system dialogs).
By default Uniwind uses "system" theme - follows device color scheme. If user wants to override it, just call Uniwind.setTheme with desired theme. It can be done above the React component to avoid theme switching at runtime.
Theme Switcher Example
import { View, Pressable, Text, ScrollView } from 'react-native';
import { Uniwind, useUniwind } from 'uniwind';
export const ThemeSwitcher = () => {
const { theme, hasAdaptiveThemes } = useUniwind();
const activeTheme = hasAdaptiveThemes ? 'system' : theme;
const themes = [
{ name: 'light', label: 'Light' },
{ name: 'dark', label: 'Dark' },
{ name: 'system', label: 'System' },
];
return (
<ScrollView horizontal showsHorizontalScrollIndicator={false}>
<View className="flex-row gap-2 p-4">
{themes.map((t) => (
<Pressable
key={t.name}
onPress={() => Uniwind.setTheme(t.name)}
className={`px-4 py-3 rounded-lg items-center ${
activeTheme === t.name ? 'bg-primary' : 'bg-card border border-border'
}`}
>
<Text className={`text-sm ${
activeTheme === t.name ? 'text-white' : 'text-foreground'
}`}>
{t.label}
</Text>
</Pressable>
))}
</View>
</ScrollView>
);
};
ScopedTheme
Apply a different theme to a subtree without changing the global theme:
import { ScopedTheme } from 'uniwind';
<View className="gap-3">
<PreviewCard />
<ScopedTheme theme="dark">
<PreviewCard /> {/* Renders with dark theme */}
</ScopedTheme>
<ScopedTheme theme="ocean">
<PreviewCard /> {/* Renders with ocean theme */}
</ScopedTheme>
</View>
- Nearest
ScopedThemewins (nested scopes supported) - Hooks (
useUniwind,useResolveClassNames,useCSSVariable) resolve against the nearest scoped theme withUniwind-wrapped components inside the scope also resolve scoped theme values- Custom themes require registration in
extraThemes
useCSSVariable
Access CSS variable values in JavaScript:
import { useCSSVariable } from 'uniwind';
const primaryColor = useCSSVariable('--color-primary');
const spacing = useCSSVariable('--spacing-4');
// Multiple variables at once
const [bg, fg] = useCSSVariable(['--color-background', '--color-foreground']) as [string, string]
Use for: animations, chart libraries, third-party component configs, calculations with design tokens.
It's required to cast the result of useCSSVariable as it can return: string | number | undefined.
Uniwind doesn't know if given variable exist and what type it is, so it returns union type.
Runtime CSS Variable Updates
Update theme variables at runtime (e.g., user-selected brand colors or API-driven themes):
Uniwind.updateCSSVariables('light', {
'--color-primary': '#ff6600',
'--color-background': '#fafafa',
});
Updates are theme-specific and take effect immediately.
@theme static
For JS-only values not used in classNames:
@theme static {
--chart-line-width: 2;
--chart-dot-radius: 4;
--animation-duration: 300;
}
Access via useCSSVariable('--chart-line-width'). Use for: chart configs, animation durations, native module values.
OKLCH Colors support
Perceptually uniform color format — wider gamut, consistent lightness:
@layer theme {
:root {
@variant light {
--color-primary: oklch(0.5 0.2 240);
--color-background: oklch(1 0 0);
}
@variant dark {
--color-primary: oklch(0.6 0.2 240);
--color-background: oklch(0.13 0.004 17.69);
}
}
}
Platform Selectors
Apply platform-specific styles directly in className:
// Individual platforms
<View className="ios:bg-red-500 android:bg-blue-500 web:bg-green-500" />
// native: shorthand (iOS + Android)
<View className="native:bg-blue-500 web:bg-gray-500" />
// TV platforms
<View className="tv:p-8 android-tv:bg-black apple-tv:bg-gray-900" />
// Combine with other utilities
<View className="p-4 ios:pt-12 android:pt-6 web:pt-4" />
Platform variants in @layer theme for global values (use @variant, not @media):
@layer theme {
:root {
@variant ios { --font-sans: 'SF Pro Text'; }
@variant android { --font-sans: 'Roboto-Regular'; }
@variant web { --font-sans: 'Inter'; }
}
}
Prefer platform selectors over Platform.select() — cleaner syntax, no imports needed.
Data Selectors
Style based on prop values using data-[prop=value]:utility:
// Boolean props
<Pressable
data-selected={isSelected}
className="border rounded px-3 py-2 data-[selected=true]:ring-2 data-[selected=true]:ring-primary"
/>
// String props
<View
data-state={isOpen ? 'open' : 'closed'}
className="p-4 data-[state=open]:bg-muted/50 data-[state=closed]:bg-transparent"
/>
// Tabs pattern
<Pressable
data-selected={route.key === current}
className="px-4 py-2 rounded-md text-foreground/60
data-[selected=true]:bg-primary data-[selected=true]:text-white"
>
<Text>{route.title}</Text>
</Pressable>
// Toggle pattern
<Pressable
data-checked={enabled}
className="h-6 w-10 rounded-full bg-muted data-[checked=true]:bg-primary"
>
<View className="h-5 w-5 rounded-full bg-background translate-x-0 data-[checked=true]:translate-x-4" />
</Pressable>
Rules:
- Only equality selectors supported (
data-[prop=value]) - No presence-only selectors (
data-[prop]— not supported) - No
has-data-*parent selectors (not supported in React Native) - Booleans match both boolean and string forms
Interactive States
// active: — when pressed
<Pressable className="bg-primary active:bg-primary/80 active:opacity-90 active:scale-95">
<Text className="text-white">Press me</Text>
</Pressable>
// disabled: — when disabled prop is true
<Pressable
disabled={isLoading}
className="bg-primary disabled:bg-gray-300 disabled:opacity-50"
>
<Text className="text-white disabled:text-gray-500">Submit</Text>
</Pressable>
// focus: — keyboard/accessibility focus
<TextInput
className="border border-border rounded-lg px-4 py-2 focus:border-primary focus:ring-2 focus:ring-primary/20"
/>
<Pressable className="bg-card rounded-lg p-4 focus:ring-2 focus:ring-primary">
<Text className="text-foreground">Focusable</Text>
</Pressable>
Components with state support:
- Pressable:
active:,disabled:,focus: - TextInput:
active:,disabled:,focus: - Switch:
disabled: - Text:
active:,disabled: - TouchableOpacity / TouchableHighlight / TouchableNativeFeedback / TouchableWithoutFeedback:
active:,disabled:
Responsive Breakpoints
Mobile-first — unprefixed styles apply to all sizes, prefixed styles apply at that breakpoint and above:
| Prefix | Min Width | Typical Device |
|---|---|---|
| (none) | 0px | All (mobile) |
sm: | 640px | Large phones |
md: | 768px | Tablets |
lg: | 1024px | Landscape tablets |
xl: | 1280px | Desktops |
2xl: | 1536px | Large desktops |
// Responsive padding and typography
<View className="p-4 sm:p-6 lg:p-8">
<Text className="text-base sm:text-lg lg:text-xl font-bold">Responsive</Text>
</View>
// Responsive grid (1 col → 2 col → 3 col)
<View className="flex-row flex-wrap">
<View className="w-full sm:w-1/2 lg:w-1/3 p-2">
<View className="bg-card p-4 rounded"><Text>Item</Text></View>
</View>
</View>
// Responsive visibility
<View className="hidden sm:flex flex-row gap-4">
<Text>Visible on tablet+</Text>
</View>
<View className="flex sm:hidden">
<Text>Mobile only</Text>
</View>
Custom breakpoints:
@theme {
--breakpoint-xs: 480px;
--breakpoint-tablet: 820px;
--breakpoint-3xl: 1920px;
}
Usage: xs:p-2 tablet:p-4 3xl:p-8
Design mobile-first — start with base styles (no prefix), enhance with breakpoints:
// CORRECT — mobile-first
<View className="w-full sm:w-3/4 md:w-1/2 lg:w-1/3" />
// WRONG — desktop-first (reversed order is confusing and fragile)
<View className="w-full lg:w-1/2 md:w-3/4 sm:w-full" />
Safe Area Utilities
Padding
| Class | Description |
|---|---|
p-safe | All sides |
pt-safe / pb-safe / pl-safe / pr-safe | Individual sides |
px-safe / py-safe | Horizontal / vertical |
Margin
| Class | Description |
|---|---|
m-safe | All sides |
mt-safe / mb-safe / ml-safe / mr-safe | Individual sides |
mx-safe / my-safe | Horizontal / vertical |
Positioning
| Class | Description |
|---|---|
inset-safe | All sides |
top-safe / bottom-safe / left-safe / right-safe | Individual sides |
x-safe / y-safe | Horizontal / vertical inset |
Compound Variants
| Pattern | Behavior | Example |
|---|---|---|
{prop}-safe-or-{value} | Math.max(inset, value) — ensures minimum spacing | pt-safe-or-4 |
{prop}-safe-offset-{value} | inset + value — adds extra spacing on top of inset | pb-safe-offset-4 |
Setup
Uniwind Free (default) — requires react-native-safe-area-context to update insets.
Wrap your App component in SafeAreaProvider and SafeAreaListener and call Uniwind.updateInsets(insets) in the onChange callback:
import { SafeAreaProvider, SafeAreaListener } from 'react-native-safe-area-context';
import { Uniwind } from 'uniwind';
export default function App() {
return (
<SafeAreaProvider>
<SafeAreaListener
onChange={({ insets }) => {
Uniwind.updateInsets(insets);
}}
>
<View className="pt-safe px-safe">{/* content */}</View>
</SafeAreaListener>
</SafeAreaProvider>
);
}
Uniwind Pro — automatic, no setup needed. Insets injected from native layer.
CSS Functions
Uniwind provides CSS functions for device-aware and theme-aware styling. These can be used everywhere (custom CSS classes, @utility, etc.) — but NOT inside @theme {} (which only accepts static values). Use @utility to create reusable Tailwind-style utility classes:
hairlineWidth()
Returns the thinnest line width displayable on the device. Use for subtle borders and dividers.
@utility h-hairline { height: hairlineWidth(); }
@utility border-hairline { border-width: hairlineWidth(); }
@utility w-hairline { width: calc(hairlineWidth() * 10); }
<View className="h-hairline bg-gray-300" />
<View className="border-hairline border-gray-200 rounded-lg p-4" />
fontScale(multiplier?)
Multiplies a base value by the device's font scale accessibility setting. Ensures text respects user preferences for larger or smaller text.
fontScale()— uses multiplier 1 (device font scale × 1)fontScale(0.9)— smaller scalefontScale(1.2)— larger scale
@utility text-sm-scaled { font-size: fontScale(0.9); }
@utility text-base-scaled { font-size: fontScale(); }
@utility text-lg-scaled { font-size: fontScale(1.2); }
<Text className="text-sm-scaled text-gray-600">Small accessible text</Text>
<Text className="text-base-scaled">Regular accessible text</Text>
pixelRatio(multiplier?)
Multiplies a value by the device's pixel ratio. Creates pixel-perfect designs that scale across screen densities.
pixelRatio()— uses multiplier 1 (device pixel ratio × 1)pixelRatio(2)— double the pixel ratio
@utility w-icon { width: pixelRatio(); }
@utility w-avatar { width: pixelRatio(2); }
<Image source={{ uri: 'avatar.png' }} className="w-avatar rounded-full" />
light-dark(lightValue, darkValue)
Returns different values based on the current theme mode. Automatically adapts when the theme changes — no manual switching logic needed.
- First parameter: value for light theme
- Second parameter: value for dark theme
@utility bg-adaptive { background-color: light-dark(#ffffff, #1f2937); }
@utility text-adaptive { color: light-dark(#111827, #f9fafb); }
@utility border-adaptive { border-color: light-dark(#e5e7eb, #374151); }
<View className="bg-adaptive border-adaptive border rounded-lg p-4">
<Text className="text-adaptive">Adapts to light/dark theme</Text>
</View>
Also works in custom CSS classes (not just @utility):
.adaptive-card {
background-color: light-dark(#ffffff, #1f2937);
color: light-dark(#111827, #f9fafb);
}
Custom CSS & Utilities
Custom CSS Classes
Uniwind supports custom CSS class names defined in global.css. They are compiled at build time — no runtime overhead. Use them when you need styles that are hard to express as Tailwind utilities (e.g., complex box-shadow, multi-property bundles).
/* global.css */
.card-shadow {
background-color: white;
border-radius: 12px;
box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}
.adaptive-surface {
background-color: light-dark(#ffffff, #1f2937);
color: light-dark(#111827, #f9fafb);
}
.container {
flex: 1;
width: 100%;
max-width: 1200px;
}
Apply via className just like any Tailwind class:
<View className="card-shadow" />
Mixing Custom CSS with Tailwind
You can combine custom CSS classes with Tailwind utilities in a single className:
<View className="card-shadow p-4 m-2">
<Text className="adaptive-surface mb-2">{title}</Text>
<View className="container flex-row">{children}</View>
</View>
WARNING: If a custom CSS class and a Tailwind utility set the same property, you MUST use cn() to deduplicate. Without cn(), both values apply and the result is unpredictable:
// WRONG — .container sets flex:1, and flex-1 also sets flex:1 (harmless but wasteful)
// WRONG — .container sets width:100%, and w-full also sets width:100% (redundant)
// DANGEROUS — .card-shadow sets border-radius:12px, and rounded-2xl sets border-radius:16px — CONFLICT!
<View className="card-shadow rounded-2xl" />
// CORRECT — cn ensures rounded-2xl wins
import { cn } from '@/lib/cn';
<View className={cn('card-shadow', 'rounded-2xl')} />
Rule of thumb: If your custom CSS class sets properties that might overlap with Tailwind utilities you'll also use, always wrap with cn(). See cn Utility section for full setup.
Guidelines for Custom CSS
- Keep selectors flat — no deep nesting or child selectors
- Prefer Tailwind utilities for simple, single-property styles
- Use custom classes for complex or multi-property bundles that would be verbose in className
- Use
light-dark()for theme-aware custom classes - Custom classes are great for shared design tokens that don't fit Tailwind's naming (e.g.,
.card,.chip,.badge-dot)
Custom Utilities (@utility)
The @utility directive creates utility classes that work exactly like built-in Tailwind classes. Use for CSS functions and patterns Tailwind doesn't support natively:
@utility h-hairline { height: hairlineWidth(); }
@utility text-scaled { font-size: fontScale(); }
Usage like any Tailwind class: <View className="h-hairline" />
@theme Directive
Customize Tailwind design tokens in global.css:
@theme {
/* Colors */
--color-primary: #3b82f6;
--color-brand-500: #3b82f6;
--color-brand-900: #1e3a8a;
/* Typography */
--font-sans: 'Roboto-Regular';
--font-sans-medium: 'Roboto-Medium';
--font-sans-bold: 'Roboto-Bold';
--font-mono: 'FiraCode-Regular';
/* Spacing & sizing */
--text-base: 15px;
--spacing-4: 16px;
--radius-lg: 12px;
/* Breakpoints */
--breakpoint-tablet: 820px;
}
Usage: bg-brand-500, text-brand-900, font-sans, font-mono, rounded-lg.
Fonts
React Native requires a single font per family — no fallbacks:
@theme {
--font-sans: 'Roboto-Regular';
--font-sans-bold: 'Roboto-Bold';
--font-mono: 'FiraCode-Regular';
}
Font name must exactly match the font file name (without extension).
Expo: Configure fonts in app.json with the expo-font plugin, then reference in CSS.
Bare RN: Use react-native-asset to link fonts, same CSS config.
Platform-specific fonts (use @variant, not @media):
@layer theme {
:root {
@variant ios { --font-sans: 'SF Pro Text'; }
@variant android { --font-sans: 'Roboto-Regular'; }
@variant web { --font-sans: 'system-ui'; }
}
}
Gradients
Built-in support — no extra dependencies:
<View className="bg-gradient-to-r from-red-500 via-yellow-500 to-green-500 p-4 rounded-lg">
<Text className="text-white font-bold">Gradient</Text>
</View>
For expo-linear-gradient, you can wrap it with withUniwind for className-based layout and styling (padding, border-radius, flex, etc.), but the colors prop is an array that cannot be resolved via className — it must be provided explicitly. Use useCSSVariable to get theme-aware colors:
import { useCSSVariable } from 'uniwind';
import { withUniwind } from 'uniwind';
import { LinearGradient as RNLinearGradient } from 'expo-linear-gradient';
const LinearGradient = withUniwind(RNLinearGradient);
function GradientCard() {
// useCSSVariable returns string | number | undefined
const primary = useCSSVariable('--color-primary');
const secondary = useCSSVariable('--color-secondary');
// Guard against undefined — LinearGradient.colors requires valid ColorValues
if (!primary || !secondary) {
return null;
}
return (
<LinearGradient
className="flex-1 rounded-2xl p-6"
colors={[primary as string, secondary as string]}
>
<Text className="text-white font-bold">Themed gradient</Text>
</LinearGradient>
);
}
Alternatively, export a wrapped component from a shared module for reuse:
// components/styled.ts
import { withUniwind } from 'uniwind';
import { LinearGradient as RNLinearGradient } from 'expo-linear-gradient';
export const LinearGradient = withUniwind(RNLinearGradient);
// usage — className handles layout, colors still passed manually
import { LinearGradient } from '@/components/styled';
<LinearGradient className="rounded-xl p-4" colors={['#ff6b6b', '#4ecdc4']}>
<Text className="text-white">Static gradient</Text>
</LinearGradient>
React Navigation Integration
Use useResolveClassNames for screen options that only accept style objects:
import { useResolveClassNames } from 'uniwind';
function Layout() {
const headerStyle = useResolveClassNames('bg-background');
const headerTitleStyle = useResolveClassNames('text-foreground font-bold');
return (
<Stack.Navigator
screenOptions={{
headerStyle,
headerTitleStyle,
}}
/>
);
}
Keep React Navigation's <ThemeProvider> if already in use — it manages navigation-specific theming.
UI Kit Compatibility
- HeroUI Native: Works with Uniwind. Uses
tailwind-variants(tv) internally. ApplyclassNamedirectly on HeroUI components. Bun users: Bun uses symlinks fornode_modules, which can cause Tailwind's Oxide scanner to miss library classes in production builds. Fix: use the resolved path in@sourceand hoist the package:@source "../../node_modules/heroui-native/lib";# .npmrc public-hoist-pattern[]=heroui-native - react-native-reusables: Compatible.
- Gluestack v4.1+: Compatible.
- Lucide React Native: Use
withUniwind(LucideIcon)withcolorClassName="accent-blue-500"for icon color. Works for all Lucide icons. - @shopify/flash-list: Use
withUniwind(FlashList)forclassNameandcontentContainerClassNamesupport. Note:withUniwindloses generic type params onref— cast manually if needed.
Use semantic color tokens (bg-primary, text-foreground) for theme consistency across UI kits.
Supported vs Unsupported Classes
React Native uses the Yoga layout engine. Key differences from web CSS:
- No CSS cascade/inheritance — styles don't inherit from parents
- Flexbox by default — all views use flexbox with
flexDirection: 'column' - Limited CSS properties — no floats, grid, pseudo-elements
Supported (all standard Tailwind)
Layout, spacing, sizing, typography, colors, borders, effects, flexbox, positioning, transforms, interactive states.
Unsupported (web-specific, silently ignored)
hover:visited:— use Pressableactive:insteadbefore:after:placeholder:— pseudo-elementsfloat-*clear-*columns-*print:screen:break-before-*break-after-*break-inside-*
Uniwind Pro
Paid upgrade with 100% API compatibility. Built on a 2nd-generation C++ engine for apps that demand the best performance. $99/seat (billed annually). Pricing and licensing: https://uniwind.dev/pricing
Pricing & Licensing
- $99/seat per year (VAT excluded unless applicable)
- Individual License: Personal Pro license per engineer
- Team License: Single key management — add or remove members instantly
- CI/CD License: Full support for automated and headless build environments
- Enterprise: Custom plans available (contact support@uniwind.dev)
- Priority Support: Critical issues resolved with priority response times
Overview
- C++ style engine: Forged on the 2nd-gen Unistyles C++ engine. Injects styles directly into the ShadowTree without triggering React re-renders — a direct, optimized highway between classNames and the native layer
- Performance: Benchmarked at ~55ms (vs StyleSheet 49ms, traditional Uniwind 81ms, NativeWind 197ms) — near-native speed
- 40+ className props update without re-renders (all component bindings listed above)
- Reanimated animations:
animate-*andtransition-*via className (Reanimated v4) - Native insets & runtime values: Automatic safe area injection, device rotation, and font size updates — no
SafeAreaListenersetup needed - Theme transitions: Native animated transitions when switching themes (fade, slide, circle mask)
- Priority support: Don't let technical hurdles slow your team down
Package: "uniwind": "npm:uniwind-pro@rc" in package.json.
Installation
-
Set dependency alias in
package.json:{ "dependencies": { "uniwind": "npm:uniwind-pro@rc" } } -
Install peer dependencies:
npm install react-native-nitro-modules react-native-reanimated react-native-worklets -
Authenticate:
npx uniwind-pro(interactive — select "Login with GitHub") -
Add Babel plugin:
// babel.config.js module.exports = { presets: ['module:metro-react-native-babel-preset'], plugins: ['react-native-worklets/plugin'], }; -
Whitelist postinstall if needed:
- bun: Add
"trustedDependencies": ["uniwind"]topackage.json - yarn v2+: Configure in
.yarnrc.yml - pnpm:
pnpm config set enable-pre-post-scripts true
- bun: Add
-
Rebuild native app:
npx expo prebuild --clean && npx expo run:ios
Pro does NOT work with Expo Go. Requires native rebuild.
Verify installation: Check for native modules (.cpp, .mm files) in node_modules/uniwind.
Reanimated Animations (Requires Reanimated v4.0.0+)
<View className="size-32 bg-primary rounded animate-spin" />
<View className="size-32 bg-primary rounded animate-bounce" />
<View className="size-32 bg-primary rounded animate-pulse" />
<View className="size-32 bg-primary rounded animate-ping" />
// Loading spinner
<View className="size-8 border-4 border-gray-200 border-t-blue-500 rounded-full animate-spin" />
Components auto-swap to Animated versions when animation classes detected:
| Component | Animated Version |
|---|---|
View | Animated.View |
Text | Animated.Text (iOS only — no Android support from Reanimated) |
Image | Animated.Image |
ImageBackground | Animated.ImageBackground |
ScrollView | Animated.ScrollView |
FlatList | Animated.FlatList |
TextInput | Animated.TextInput (iOS only) |
Pressable | Animated.View wrapper |
Transitions
Smooth property changes when className or state changes:
// Color transition on press
<Pressable className="bg-primary active:bg-red-500 transition-colors duration-300" />
// Opacity transition
<View className={`transition-opacity duration-500 ${visible ? 'opacity-100' : 'opacity-0'}`} />
// Transform transition
<Pressable className="active:scale-95 transition-transform duration-150" />
// All properties
<Pressable className="bg-primary px-6 py-3 rounded-lg active:scale-95 active:bg-primary/80 transition-all duration-150">
<Text className="text-white font-semibold">Animated Button</Text>
</Pressable>
| Class | Properties |
|---|---|
transition-none | No transition |
transition-all | All properties |
transition-colors | Background, border, text colors |
transition-opacity | Opacity |
transition-shadow | Box shadow |
transition-transform | Scale, rotate, translate |
Duration: duration-75 duration-100 duration-150 duration-200 duration-300 duration-500 duration-700 duration-1000
Easing: ease-linear ease-in ease-out ease-in-out
Delay: delay-75 delay-100 delay-150 delay-200 delay-300 delay-500 delay-700 delay-1000
Using Reanimated Directly
Still works with Uniwind classes:
import Animated, { FadeIn, FlipInXUp, LinearTransition } from 'react-native-reanimated';
<Animated.Text entering={FadeIn.delay(500)} className="text-foreground text-lg">
Fading in
</Animated.Text>
<Animated.FlatList
data={data}
className="flex-none"
contentContainerClassName="px-2"
layout={LinearTransition}
renderItem={({ item }) => (
<Animated.Text entering={FlipInXUp} className="text-foreground py-2">
{item}
</Animated.Text>
)}
/>
Shadow Tree Updates
No code changes needed — props connect directly to C++ engine, eliminating re-renders automatically.
Native Insets
Remove SafeAreaListener setup — insets injected from native layer:
// With Pro — just use safe area classes directly
<View className="pt-safe pb-safe">{/* content */}</View>
Theme Transitions (Pro)
Native animated transitions when switching themes. Import ThemeTransitionPreset and pass to setTheme:
import { Uniwind, ThemeTransitionPreset } from 'uniwind';
// Fade transition
Uniwind.setTheme('dark', ThemeTransitionPreset.Fade);
// Slide transitions
Uniwind.setTheme('dark', ThemeTransitionPreset.SlideRightToLeft);
Uniwind.setTheme('light', ThemeTransitionPreset.SlideLeftToRight);
// Circle mask transitions (expand from a corner or center)
Uniwind.setTheme('ocean', ThemeTransitionPreset.CircleCenter);
Uniwind.setTheme('dark', ThemeTransitionPreset.CircleTopRight);
// No animation
Uniwind.setTheme('light', ThemeTransitionPreset.None);
Available presets:
| Preset | Effect |
|---|---|
ThemeTransitionPreset.None | Instant switch, no animation |
ThemeTransitionPreset.Fade | Crossfade between themes |
ThemeTransitionPreset.SlideRightToLeft | Slide new theme in from right |
ThemeTransitionPreset.SlideLeftToRight | Slide new theme in from left |
ThemeTransitionPreset.CircleTopRight | Circle mask expanding from top-right |
ThemeTransitionPreset.CircleTopLeft | Circle mask expanding from top-left |
ThemeTransitionPreset.CircleBottomRight | Circle mask expanding from bottom-right |
ThemeTransitionPreset.CircleBottomLeft | Circle mask expanding from bottom-left |
ThemeTransitionPreset.CircleCenter | Circle mask expanding from center |
Setup Diagnostics
When styles aren't working, check in this order:
1. package.json
"uniwind"(or"uniwind-pro") in dependencies"tailwindcss"at v4+ (^4.0.0)- For Pro:
react-native-nitro-modules,react-native-reanimated,react-native-worklets
2. metro.config.js
withUniwindConfigimported from'uniwind/metro'withUniwindConfigis the outermost wrappercssEntryFileis a relative path string (e.g.,'./global.css')- No
path.resolve()or absolute paths
3. global.css
- Contains
@import 'tailwindcss';AND@import 'uniwind'; - Imported in
App.tsxor root layout, NOT inindex.ts/index.js - Location determines app root for Tailwind scanning
4. babel.config.js (Pro only)
'react-native-worklets/plugin'in plugins array
5. TypeScript
uniwind-types.d.tsexists (generated after running Metro)- Included in
tsconfig.jsonor placed insrc//app/dir
6. Build
- Metro server restarted after config changes
- Metro cache cleared (
npx expo start --clearornpx react-native start --reset-cache) - Native rebuild done (if Pro or after dependency changes)
Troubleshooting
| Symptom | Cause | Fix |
|---|---|---|
| Styles not applying | Missing imports in global.css | Add @import 'tailwindcss'; @import 'uniwind'; |
| Styles not applying | global.css imported in index.js | Move import to App.tsx or _layout.tsx |
| Classes not detected | global.css in nested dir, components elsewhere | Add @source '../components' in global.css |
| TypeScript errors on className | Missing types file | Run Metro to generate uniwind-types.d.ts |
withUniwindConfig is not a function | Wrong import | Use require('uniwind/metro') not require('uniwind') |
| Hot reload full-reloads | global.css imported in wrong file | Move to App.tsx or root layout |
cssEntryFile error / Metro crash | Absolute path used | Use relative: './global.css' |
withUniwindConfig not outermost | Another wrapper wraps Uniwind | Swap order so Uniwind is outermost |
| Dark theme not working | Missing @variant dark | Define dark variant in @layer theme |
| Custom theme not appearing | Not registered in metro config | Add to extraThemes array, restart Metro |
| Fonts not loading | Font name mismatch | CSS font name must match file name exactly (no extension) |
rem values too large/small | Wrong base rem | Set polyfills: { rem: 14 } for NativeWind compat |
| Unsupported CSS warning | Web-specific CSS used | Enable debug: true to identify; remove unsupported properties |
Failed to serialize javascript object | Complex CSS, circular refs, or stale cache | Clear caches: watchman watch-del-all; rm -rf node_modules/.cache; npx expo start --clear. Also check if docs/markdown files containing CSS classes are in the scan path (see below) |
Failed to serialize javascript object from llms-full.txt or docs | Docs/markdown files with CSS classes in project dir get scanned by Tailwind | Move .md files with CSS examples outside the project root, or add to .gitignore so Tailwind's scanner skips them |
unstable_enablePackageExports conflict | App disables package exports | Use selective resolver for Uniwind and culori |
| Classes from monorepo package missing | Not included in Tailwind scan | Add @source '../../packages/ui' in global.css |
Classes from node_modules library missing in production (bun) | Bun uses symlinks; Tailwind's Oxide scanner can't follow them | Use resolved path: @source "../../node_modules/heroui-native/lib" and add public-hoist-pattern[]=heroui-native to .npmrc |
active: not working with withUniwind | withUniwind does NOT support interactive state selectors | Only core RN Pressable/TextInput/Switch support active:/focus:/disabled:. Third-party pressables wrapped with withUniwind won't get states |
withUniwind custom mapping overrides className+style merging | When manual mapping is provided, style prop is not merged | Use auto mapping (no second arg) for className+style merge. For manual mapping + className, double-wrap: withUniwind(withUniwind(Comp), { mapping }) |
withUniwind loses generic types on ref (e.g., FlashList<T>) | TypeScript limitation with HOCs | Cast the ref manually: ref={scrollRef as any} |
Platform-specific fonts: @theme block error | @media ios/android inside @theme {} | Use @layer theme { :root { @variant ios { ... } } } instead — @theme only accepts custom properties, and platform selection uses @variant not @media |
Uniwind.setTheme('system') crash on Android (RN 0.82+) | RN 0.82 changed Appearance API | Update to latest Uniwind (fixed). Avoid setTheme('system') on older Uniwind + RN 0.82+ |
| Styles flash/disappear on initial load (Android) | SafeAreaListener fires before component listeners mount | Fixed in recent versions. If persists, ensure Uniwind is latest |
useTVEventHandler is undefined | Uniwind module replacement interferes with tvOS exports | Fixed in v1.2.1+. Update Uniwind |
@layer theme variables not rendering on web | Bug with RNW + Expo SDK 55 | Fixed in v1.4.1+. Update Uniwind |
updateCSSVariables wrong theme at app start | Calling for multiple themes back-to-back; last call wins on first render | Call updateCSSVariables for the current theme last. After initial load, order doesn't matter |
| Pro: animations not working | Missing Babel plugin | Add react-native-worklets/plugin to babel.config.js |
| Pro: module not found | No native rebuild | Run npx expo prebuild --clean then npx expo run:ios |
| Pro: postinstall failed | Package manager blocks scripts | Add to trustedDependencies (bun) or configure yarn/pnpm |
| Pro: auth expired | Login session expired (180-day lifetime) | Run npx uniwind-pro, re-login |
| Pro: download limit reached | Monthly download limit hit | Check Pro dashboard, limits reset monthly |
Pro: Uniwind.updateInsets called unnecessarily | Pro injects insets natively | Uniwind.updateInsets is a no-op in Pro. Remove SafeAreaListener setup when using Pro |
| Pro: theme transition crash | Missing ThemeTransitionPreset import or calling before app is ready | Import from 'uniwind'. Ensure the app has fully mounted before calling setTheme with a transition |
unstable_enablePackageExports Selective Resolver
If your app disables unstable_enablePackageExports (common in crypto apps), use a selective resolver:
config.resolver.unstable_enablePackageExports = false;
config.resolver.resolveRequest = (context, moduleName, platform) => {
if (['uniwind', 'culori'].some((prefix) => moduleName.startsWith(prefix))) {
return context.resolveRequest(
{ ...context, unstable_enablePackageExports: true },
moduleName,
platform
);
}
return context.resolveRequest(context, moduleName, platform);
};
FAQ
Where to put global.css in Expo Router?
Project root. Import in app/_layout.tsx. If placed in app/, add @source for sibling dirs.
Does Uniwind work with Expo Go? Free: Yes. Pro: No — requires native rebuild (development builds).
Can I use tailwind.config.js?
No. Uniwind uses Tailwind v4 — all config via @theme in global.css.
How to access CSS variables in JS?
useCSSVariable('--color-primary'). For variables not used in classNames, define with @theme static.
Can I use Platform.select()?
Yes, but prefer platform selectors (ios:pt-12 android:pt-6) — cleaner, no imports.
Next.js support?
Not officially supported. Community plugin: uniwind-plugin-next. For Next.js, use standard Tailwind CSS.
Vite support?
Yes, since v1.2.0. Use uniwind/vite plugin alongside @tailwindcss/vite.
Full app reloads on CSS changes?
Metro can't hot-reload files with many providers. Move global.css import deeper in the component tree.
Style specificity?
Inline style always overrides className. Use className for static styles, inline only for truly dynamic values. Use cn() from tailwind-merge for component libraries where classNames may conflict.
How do I include custom fonts?
Load font files (Expo: expo-font plugin in app.json; Bare RN: react-native-asset), then map in CSS: @theme { --font-sans: 'Roboto-Regular'; }. Font name must exactly match the file name. See the Fonts section above.
How can I style based on prop values?
Use data selectors: data-[selected=true]:ring-2. Only equality checks supported. See the Data Selectors section above.
How can I use gradients?
Built-in: bg-gradient-to-r from-red-500 to-green-500. Also supports angle-based (bg-linear-90) and arbitrary values (bg-linear-[45deg,#f00_0%,#00f_100%]). See the Gradients section above.
How does className deduplication work?
Uniwind does NOT auto-deduplicate conflicting classNames. Use tailwind-merge with a cn() utility. See the cn Utility section above.
How to debug 'Failed to serialize javascript object'?
Clear caches: watchman watch-del-all; rm -rf node_modules/.cache; npx expo start --clear. Enable debug: true in metro config to identify the problematic CSS pattern. See the Troubleshooting table above.
How do I enable safe area classNames?
Free: Install react-native-safe-area-context, wrap root with SafeAreaListener, call Uniwind.updateInsets(insets). Pro: Automatic — no setup. Then use pt-safe, pb-safe, etc. See the Safe Area Utilities section above.
What UI kits work well with Uniwind?
React Native Reusables (shadcn philosophy, copy-paste components) and HeroUI Native (complete library, optimized for Uniwind). Any library works via withUniwind wrapper. See the UI Kit Compatibility section above.
Can I scope a theme to a single component?
Yes, use ScopedTheme: <ScopedTheme theme="dark"><Card /></ScopedTheme>. It forces a theme for the subtree without changing the global theme. See the Theming section.
Does active: work with react-native-gesture-handler Pressable?
No. withUniwind does NOT support interactive state selectors (active:, focus:, disabled:). Only core RN Pressable, TextInput, and Switch support them. For RNGH components, use onPressIn/onPressOut with state.
Can I customize the default border color?
Not via @layer base. The default borderColor from border class is hardcoded to #000000. Use border border-gray-300 explicitly or define --color-border in @theme and use border-border.
Can I use platform-specific fonts in @theme {}?
No. @theme {} only accepts custom properties. Use @layer theme { :root { @variant ios { --font-sans: '...'; } } } instead. Note: use @variant (not @media) for platform selection in CSS.
Does Uniwind work with ESM metro config (metro.config.mjs or metro.config.ts)?
Yes since v1.3.0+. If you hit Class extends value is not a constructor, update Uniwind or use CommonJS metro.config.js.
Classes from node_modules work in dev but not production (bun)?
Bun symlinks packages. Tailwind's Oxide scanner can't follow them. Use resolved @source paths and hoist the package. See UI Kit Compatibility for details.
How to clear all caches when debugging?
watchman watch-del-all 2>/dev/null; rm -rf node_modules/.cache && npx expo start --clear. This clears Watchman, Babel/bundler caches, and Expo internal cache.
MCP Server
Uniwind provides an official MCP server for AI-assisted development. If the user's environment supports MCP, recommend setting it up: https://docs.uniwind.dev/mcp
Related Skills
NativeWind → Uniwind migration: Use the migrate-nativewind-to-uniwind skill for migrating from NativeWind. It handles package removal, config migration, Tailwind v4 upgrade, cssInterop removal, theme conversion, and all breaking changes. It is tested and production-ready.
IMPORTANT: Do NOT guess Uniwind APIs. If you are unsure about any Uniwind API, hook, component, or configuration option, fetch and verify against the official docs: https://docs.uniwind.dev/llms-full.txt