A set of tools to manage inline styles on React elements


npm install radium

Radium is a set of tools to manage inline styles on React elements. It gives you powerful styling capabilities without CSS.

Inspired by React: CSS in JS by vjeux.

Eliminating CSS in favor of inline styles that are computed on the fly is a powerful approach, providing a number of benefits over traditional CSS:

  • Scoped styles without selectors
  • Avoids specificity conflicts
  • Source order independence
  • Dead code elimination
  • Highly expressive

Despite that, there are some common CSS features and techniques that inline styles don't easily accommodate: media queries, browser states (:hover, :focus, :active) and modifiers (no more .btn-primary!). Radium offers a standard interface and abstractions for dealing with these problems.

When we say expressive, we mean it: math, concatenation, regex, conditionals, functions–JavaScript is at your disposal. Modern web applications demand that the display changes when data changes, and Radium is here to help.

For a short technical explanation, see How does Radium work?.

Convinced about CSS in JS with React, but not Radium? Check out our comprehensive comparison of 14+ alternatives.

  • Conceptually simple extension of normal inline styles
  • Browser state styles to support :hover, :focus, and :active
  • Media queries
  • Automatic vendor prefixing
  • Keyframes animation helper
  • ES6 class and createClass support

Start by adding the @Radium decorator to your component class. Alternatively, wrap Radium() around your component, like module.exports = Radium(Component), or Component = Radium(Component), which works with classes, createClass, and stateless components (functions that take props and return a ReactElement). Then, write a style object as you normally would with inline styles, and add in styles for interactive states and media queries. Pass the style object to your component via style={...} and let Radium do the rest!

<Button kind="primary">Radium Button</Button>
var Radium = require('radium');
var React = require('react');
var color = require('color');
class Button extends React.Component {
  static propTypes = {
    kind: React.PropTypes.oneOf(['primary', 'warning']).isRequired
  render() {
    // Radium extends the style attribute to accept an array. It will merge
    // the styles in order. We use this feature here to apply the primary
    // or warning styles depending on the value of the `kind` prop. Since its
    // all just JavaScript, you can use whatever logic you want to decide which
    // styles are applied (props, state, context, etc).
    return (
// You can create your style objects dynamically or share them for
// every instance of the component.
var styles = {
  base: {
    color: '#fff',
    // Adding interactive state couldn't be easier! Add a special key to your
    // style object (:hover, :focus, :active, or @media) with the additional rules.
    ':hover': {
      background: color('#0074d9').lighten(0.2).hexString()
  primary: {
    background: '#0074D9'
  warning: {
    background: '#FF4136'

To see the universal examples:

npm install
npm run universal

To see local client-side only examples in action, do this:

npm install
npm run examples

Following is a short technical explanation of Radium's inner workings:

  • Wrap the render function
  • Recurse into the result of the original render
  • For each element:
    • Add handlers to props if interactive styles are specified, e.g. onMouseEnter for :hover, wrapping existing handlers if necessary
    • If any of the handlers are triggered, e.g. by hovering, Radium calls setState to update a Radium-specific field on the components state object
    • On re-render, resolve any interactive styles that apply, e.g. :hover, by looking up the element's key or ref in the Radium-specific state