Terminal string styling done right

colors.js is currently the most popular string styling module, but it has serious deficiencies like extending String.prototype which causes all kinds of problems. Although there are other ones, they either do too much or not enough.

Chalk is a clean and focused alternative.

• Doesn't extend String.prototype
• Expressive API
• Clean and focused
• Auto-detects color support
• Actively maintained
• Used by 150+ modules

Install with npm: npm install --save chalk

Chalk comes with an easy to use composable API where you just chain and nest the styles you want.

var chalk = require('chalk');

// style a string
console.log(  chalk.blue('Hello world!')  );

// combine styled and normal strings
console.log(  chalk.blue('Hello'), 'World' + chalk.red('!')  );

// compose multiple styles using the chainable API
console.log(  chalk.blue.bgRed.bold('Hello world!')  );

// nest styles
console.log(  chalk.red('Hello', chalk.underline.bgBlue('world') + '!')  );

// pass in multiple arguments
console.log(  chalk.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz')  );

Easily define your own themes.

var chalk = require('chalk');
var error = chalk.bold.red;
console.log(error('Error!'));

Take advantage of console.log string substitution.

var name = 'Sindre';
console.log(chalk.green('Hello %s'), name);
//=> Hello Sindre

Example: chalk.red.bold.underline('Hello', 'world');

Chain styles and call the last one as a method with a string argument. Order doesn't matter.

Multiple arguments will be separated by space.

Color support is automatically detected, but you can override it.

Detect whether the terminal supports color.

Can be overridden by the user with the flags --color and --no-color.

Used internally and handled for you, but exposed for convenience.

Exposes the styles as ANSI escape codes.

Generally not useful, but you might need just the .open or .close escape code if you're mixing externally styled strings with yours.

var chalk = require('chalk');

console.log(chalk.styles.red);
//=> {open: '\x1b[31m', close: '\x1b[39m'}

console.log(chalk.styles.red.open + 'Hello' + chalk.styles.red.close);

Strip color from a string.

Can be useful in combination with .supportsColor to strip color on externally styled text when it's not supported.

Example:

var chalk = require('chalk');
var styledString = fromExternal();

if (!chalk.supportsColor) {
	chalk.stripColor(styledString);
}

• reset
• bold
• italic
• underline
• inverse
• strikethrough

• black
• red
• green
• yellow
• blue
• magenta
• cyan
• white
• gray

• bgBlack
• bgRed
• bgGreen
• bgYellow
• bgBlue
• bgMagenta
• bgCyan
• bgWhite

MIT © Sindre Sorhus