> Terminal string styling done right
[](https://travis-ci.org/chalk/chalk)
[](https://coveralls.io/r/chalk/chalk?branch=master)
[](https://www.youtube.com/watch?v=9auOCbH5Ns4)
[colors.js](https://github.com/Marak/colors.js) used to be the most popular string styling module, but it has serious deficiencies like extending `String.prototype` which causes all kinds of [problems](https://github.com/yeoman/yo/issues/68). Although there are other ones, they either do too much or not enough.
**Chalk is a clean and focused alternative.**
## Why
- Highly performant
- Doesn't extend `String.prototype`
- Expressive API
- Ability to nest styles
- Clean and focused
- Auto-detects color support
- Actively maintained
- [Used by ~4500 modules](https://www.npmjs.com/browse/depended/chalk) as of July 15, 2015
## Install
```
$ npm install --save chalk
```
## Usage
Chalk comes with an easy to use composable API where you just chain and nest the styles you want.
```js
var chalk = require('chalk');
// style a string
chalk.blue('Hello world!');
// combine styled and normal strings
chalk.blue('Hello') + 'World' + chalk.red('!');
// compose multiple styles using the chainable API
chalk.blue.bgRed.bold('Hello world!');
// pass in multiple arguments
chalk.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz');
// nest styles
chalk.red('Hello', chalk.underline.bgBlue('world') + '!');
// nest styles of the same type even (color, underline, background)
chalk.green(
'I am a green line ' +
chalk.blue.underline.bold('with a blue substring') +
' that becomes green again!'
);
```
Easily define your own themes.
```js
var chalk = require('chalk');
var error = chalk.bold.red;
console.log(error('Error!'));
```
Take advantage of console.log [string substitution](http://nodejs.org/docs/latest/api/console.html#console_console_log_data).
```js
var name = 'Sindre';
console.log(chalk.green('Hello %s'), name);
//=> Hello Sindre
```
## API
### chalk.`