4 <img width="320" src="media/logo.svg" alt="Chalk">
10 > Terminal string styling done right
12 [![Build Status](https://travis-ci.org/chalk/chalk.svg?branch=master)](https://travis-ci.org/chalk/chalk) [![Coverage Status](https://coveralls.io/repos/github/chalk/chalk/badge.svg?branch=master)](https://coveralls.io/github/chalk/chalk?branch=master) [![](https://img.shields.io/badge/unicorn-approved-ff69b4.svg)](https://www.youtube.com/watch?v=9auOCbH5Ns4) [![XO code style](https://img.shields.io/badge/code_style-XO-5ed9c7.svg)](https://github.com/xojs/xo) [![Mentioned in Awesome Node.js](https://awesome.re/mentioned-badge.svg)](https://github.com/sindresorhus/awesome-nodejs)
14 ### [See what's new in Chalk 2](https://github.com/chalk/chalk/releases/tag/v2.0.0)
16 <img src="https://cdn.rawgit.com/chalk/ansi-styles/8261697c95bf34b6c7767e2cbe9941a851d59385/screenshot.svg" alt="" width="900">
23 - Ability to nest styles
24 - [256/Truecolor color support](#256-and-truecolor-color-support)
25 - Auto-detects color support
26 - Doesn't extend `String.prototype`
29 - [Used by ~23,000 packages](https://www.npmjs.com/browse/depended/chalk) as of December 31, 2017
38 <a href="https://www.patreon.com/sindresorhus">
39 <img src="https://c5.patreon.com/external/logo/become_a_patron_button@2x.png" width="160">
46 const chalk = require('chalk');
48 console.log(chalk.blue('Hello world!'));
51 Chalk comes with an easy to use composable API where you just chain and nest the styles you want.
54 const chalk = require('chalk');
55 const log = console.log;
57 // Combine styled and normal strings
58 log(chalk.blue('Hello') + ' World' + chalk.red('!'));
60 // Compose multiple styles using the chainable API
61 log(chalk.blue.bgRed.bold('Hello world!'));
63 // Pass in multiple arguments
64 log(chalk.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz'));
67 log(chalk.red('Hello', chalk.underline.bgBlue('world') + '!'));
69 // Nest styles of the same type even (color, underline, background)
71 'I am a green line ' +
72 chalk.blue.underline.bold('with a blue substring') +
73 ' that becomes green again!'
76 // ES2015 template literal
78 CPU: ${chalk.red('90%')}
79 RAM: ${chalk.green('40%')}
80 DISK: ${chalk.yellow('70%')}
83 // ES2015 tagged template literal
85 CPU: {red ${cpu.totalPercent}%}
86 RAM: {green ${ram.used / ram.total * 100}%}
87 DISK: {rgb(255,131,0) ${disk.used / disk.total * 100}%}
90 // Use RGB colors in terminal emulators that support it.
91 log(chalk.keyword('orange')('Yay for orange colored text!'));
92 log(chalk.rgb(123, 45, 67).underline('Underlined reddish color'));
93 log(chalk.hex('#DEADED').bold('Bold gray!'));
96 Easily define your own themes:
99 const chalk = require('chalk');
101 const error = chalk.bold.red;
102 const warning = chalk.keyword('orange');
104 console.log(error('Error!'));
105 console.log(warning('Warning!'));
108 Take advantage of console.log [string substitution](https://nodejs.org/docs/latest/api/console.html#console_console_log_data_args):
111 const name = 'Sindre';
112 console.log(chalk.green('Hello %s'), name);
119 ### chalk.`<style>[.<style>...](string, [string...])`
121 Example: `chalk.red.bold.underline('Hello', 'world');`
123 Chain [styles](#styles) and call the last one as a method with a string argument. Order doesn't matter, and later styles take precedent in case of a conflict. This simply means that `chalk.red.yellow.green` is equivalent to `chalk.green`.
125 Multiple arguments will be separated by space.
129 Color support is automatically detected, as is the level (see `chalk.level`). However, if you'd like to simply enable/disable Chalk, you can do so via the `.enabled` property.
131 Chalk is enabled by default unless explicitly disabled via the constructor or `chalk.level` is `0`.
133 If you need to change this in a reusable module, create a new instance:
136 const ctx = new chalk.constructor({enabled: false});
141 Color support is automatically detected, but you can override it by setting the `level` property. You should however only do this in your own code as it applies globally to all Chalk consumers.
143 If you need to change this in a reusable module, create a new instance:
146 const ctx = new chalk.constructor({level: 0});
149 Levels are as follows:
151 0. All colors disabled
152 1. Basic color support (16 colors)
154 3. Truecolor support (16 million colors)
156 ### chalk.supportsColor
158 Detect whether the terminal [supports color](https://github.com/chalk/supports-color). Used internally and handled for you, but exposed for convenience.
160 Can be overridden by the user with the flags `--color` and `--no-color`. For situations where using `--color` is not possible, add the environment variable `FORCE_COLOR=1` to forcefully enable color or `FORCE_COLOR=0` to forcefully disable. The use of `FORCE_COLOR` overrides all other color support checks.
162 Explicit 256/Truecolor mode can be enabled using the `--color=256` and `--color=16m` flags, respectively.
172 - `italic` *(Not widely supported)*
176 - `strikethrough` *(Not widely supported)*
177 - `visible` (Text is emitted only if enabled)
185 - `blue` *(On Windows the bright version is used since normal blue is illegible)*
189 - `gray` ("bright black")
198 ### Background colors
218 ## Tagged template literal
220 Chalk can be used as a [tagged template literal](http://exploringjs.com/es6/ch_template-literals.html#_tagged-template-literals).
223 const chalk = require('chalk');
226 const calculateFeet = miles => miles * 5280;
229 There are {bold 5280 feet} in a mile.
230 In {bold ${miles} miles}, there are {green.bold ${calculateFeet(miles)} feet}.
234 Blocks are delimited by an opening curly brace (`{`), a style, some content, and a closing curly brace (`}`).
236 Template styles are chained exactly like normal Chalk styles. The following two statements are equivalent:
239 console.log(chalk.bold.rgb(10, 100, 200)('Hello!'));
240 console.log(chalk`{bold.rgb(10,100,200) Hello!}`);
243 Note that function styles (`rgb()`, `hsl()`, `keyword()`, etc.) may not contain spaces between parameters.
245 All interpolated values (`` chalk`${foo}` ``) are converted to strings via the `.toString()` method. All curly braces (`{` and `}`) in interpolated value strings are escaped.
248 ## 256 and Truecolor color support
250 Chalk supports 256 colors and [Truecolor](https://gist.github.com/XVilka/8346728) (16 million colors) on supported terminal apps.
252 Colors are downsampled from 16 million RGB values to an ANSI color format that is supported by the terminal emulator (or by specifying `{level: n}` as a Chalk option). For example, Chalk configured to run at level 1 (basic color support) will downsample an RGB value of #FF0000 (red) to 31 (ANSI escape for red).
256 - `chalk.hex('#DEADED').underline('Hello, world!')`
257 - `chalk.keyword('orange')('Some orange text')`
258 - `chalk.rgb(15, 100, 204).inverse('Hello!')`
260 Background versions of these models are prefixed with `bg` and the first level of the module capitalized (e.g. `keyword` for foreground colors and `bgKeyword` for background colors).
262 - `chalk.bgHex('#DEADED').underline('Hello, world!')`
263 - `chalk.bgKeyword('orange')('Some orange text')`
264 - `chalk.bgRgb(15, 100, 204).inverse('Hello!')`
266 The following color models can be used:
268 - [`rgb`](https://en.wikipedia.org/wiki/RGB_color_model) - Example: `chalk.rgb(255, 136, 0).bold('Orange!')`
269 - [`hex`](https://en.wikipedia.org/wiki/Web_colors#Hex_triplet) - Example: `chalk.hex('#FF8800').bold('Orange!')`
270 - [`keyword`](https://www.w3.org/wiki/CSS/Properties/color/keywords) (CSS keywords) - Example: `chalk.keyword('orange').bold('Orange!')`
271 - [`hsl`](https://en.wikipedia.org/wiki/HSL_and_HSV) - Example: `chalk.hsl(32, 100, 50).bold('Orange!')`
272 - [`hsv`](https://en.wikipedia.org/wiki/HSL_and_HSV) - Example: `chalk.hsv(32, 100, 100).bold('Orange!')`
273 - [`hwb`](https://en.wikipedia.org/wiki/HWB_color_model) - Example: `chalk.hwb(32, 0, 50).bold('Orange!')`
280 If you're on Windows, do yourself a favor and use [`cmder`](http://cmder.net/) instead of `cmd.exe`.
285 [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) and the package is unmaintained. Although there are other packages, they either do too much or not enough. Chalk is a clean and focused alternative.
290 - [chalk-cli](https://github.com/chalk/chalk-cli) - CLI for this module
291 - [ansi-styles](https://github.com/chalk/ansi-styles) - ANSI escape codes for styling strings in the terminal
292 - [supports-color](https://github.com/chalk/supports-color) - Detect whether a terminal supports color
293 - [strip-ansi](https://github.com/chalk/strip-ansi) - Strip ANSI escape codes
294 - [strip-ansi-stream](https://github.com/chalk/strip-ansi-stream) - Strip ANSI escape codes from a stream
295 - [has-ansi](https://github.com/chalk/has-ansi) - Check if a string has ANSI escape codes
296 - [ansi-regex](https://github.com/chalk/ansi-regex) - Regular expression for matching ANSI escape codes
297 - [wrap-ansi](https://github.com/chalk/wrap-ansi) - Wordwrap a string with ANSI escape codes
298 - [slice-ansi](https://github.com/chalk/slice-ansi) - Slice a string with ANSI escape codes
299 - [color-convert](https://github.com/qix-/color-convert) - Converts colors between different models
300 - [chalk-animation](https://github.com/bokub/chalk-animation) - Animate strings in the terminal
301 - [gradient-string](https://github.com/bokub/gradient-string) - Apply color gradients to strings
302 - [chalk-pipe](https://github.com/LitoMore/chalk-pipe) - Create chalk style schemes with simpler style strings
303 - [terminal-link](https://github.com/sindresorhus/terminal-link) - Create clickable links in the terminal
308 - [Sindre Sorhus](https://github.com/sindresorhus)
309 - [Josh Junon](https://github.com/qix-)