chalk/readme.md

<h1 align="center">
	<br>
	<br>
	<img width="320" src="media/logo.svg" alt="Chalk">
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</h1>

> Terminal string styling done right

[![Coverage Status](https://codecov.io/gh/chalk/chalk/branch/main/graph/badge.svg)](https://codecov.io/gh/chalk/chalk)
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![](media/screenshot.png)

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---

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---

<br>

## Highlights

- Expressive API
- Highly performant
- No dependencies
- Ability to nest styles
- [256/Truecolor color support](#256-and-truecolor-color-support)
- Auto-detects color support
- Doesn't extend `String.prototype`
- Clean and focused
- Actively maintained
- [Used by ~86,000 packages](https://www.npmjs.com/browse/depended/chalk) as of October 4, 2022

## Install

```sh
npm install chalk
```

**IMPORTANT:** Chalk 5 is ESM. If you want to use Chalk with TypeScript or a build tool, you will probably want to use Chalk 4 for now. [Read more.](https://github.com/chalk/chalk/releases/tag/v5.0.0)

## Usage

```js
import chalk from 'chalk';

console.log(chalk.blue('Hello world!'));
```

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

```js
import chalk from 'chalk';

const log = console.log;

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

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

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

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

// Nest styles of the same type even (color, underline, background)
log(chalk.green(
	'I am a green line ' +
	chalk.blue.underline.bold('with a blue substring') +
	' that becomes green again!'
));

// ES2015 template literal
log(`
CPU: ${chalk.red('90%')}
RAM: ${chalk.green('40%')}
DISK: ${chalk.yellow('70%')}
`);

// Use RGB colors in terminal emulators that support it.
log(chalk.rgb(123, 45, 67).underline('Underlined reddish color'));
log(chalk.hex('#DEADED').bold('Bold gray!'));
```

Easily define your own themes:

```js
import chalk from 'chalk';

const error = chalk.bold.red;
const warning = chalk.hex('#FFA500'); // Orange color

console.log(error('Error!'));
console.log(warning('Warning!'));
```

Take advantage of console.log [string substitution](https://nodejs.org/docs/latest/api/console.html#console_console_log_data_args):

```js
import chalk from 'chalk';

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

## API

### chalk.`<style>[.<style>...](string, [string...])`

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

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`.

Multiple arguments will be separated by space.

### chalk.level

Specifies the level of color support.

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.

If you need to change this in a reusable module, create a new instance:

```js
import {Chalk} from 'chalk';

const customChalk = new Chalk({level: 0});
```

| Level | Description |
| :---: | :--- |
| `0` | All colors disabled |
| `1` | Basic color support (16 colors) |
| `2` | 256 color support |
| `3` | Truecolor support (16 million colors) |

### supportsColor

Detect whether the terminal [supports color](https://github.com/chalk/supports-color). Used internally and handled for you, but exposed for convenience.

Can be overridden by the user with the flags `--color` and `--no-color`. For situations where using `--color` is not possible, use the environment variable `FORCE_COLOR=1` (level 1), `FORCE_COLOR=2` (level 2), or `FORCE_COLOR=3` (level 3) to forcefully enable color, or `FORCE_COLOR=0` to forcefully disable. The use of `FORCE_COLOR` overrides all other color support checks.

Explicit 256/Truecolor mode can be enabled using the `--color=256` and `--color=16m` flags, respectively.

### chalkStderr and supportsColorStderr

`chalkStderr` contains a separate instance configured with color support detected for `stderr` stream instead of `stdout`. Override rules from `supportsColor` apply to this too. `supportsColorStderr` is exposed for convenience.

### modifierNames, foregroundColorNames, backgroundColorNames, and colorNames

All supported style strings are exposed as an array of strings for convenience. `colorNames` is the combination of `foregroundColorNames` and `backgroundColorNames`.

This can be useful if you wrap Chalk and need to validate input:

```js
import {modifierNames, foregroundColorNames} from 'chalk';

console.log(modifierNames.includes('bold'));
//=> true

console.log(foregroundColorNames.includes('pink'));
//=> false
```

## Styles

### Modifiers

- `reset` - Reset the current style.
- `bold` - Make the text bold.
- `dim` - Make the text have lower opacity.
- `italic` - Make the text italic. *(Not widely supported)*
- `underline` - Put a horizontal line below the text. *(Not widely supported)*
- `overline` - Put a horizontal line above the text. *(Not widely supported)*
- `inverse`- Invert background and foreground colors.
- `hidden` - Print the text but make it invisible.
- `strikethrough` - Puts a horizontal line through the center of the text. *(Not widely supported)*
- `visible`- Print the text only when Chalk has a color level above zero. Can be useful for things that are purely cosmetic.

### Colors

- `black`
- `red`
- `green`
- `yellow`
- `blue`
- `magenta`
- `cyan`
- `white`
- `blackBright` (alias: `gray`, `grey`)
- `redBright`
- `greenBright`
- `yellowBright`
- `blueBright`
- `magentaBright`
- `cyanBright`
- `whiteBright`

### Background colors

- `bgBlack`
- `bgRed`
- `bgGreen`
- `bgYellow`
- `bgBlue`
- `bgMagenta`
- `bgCyan`
- `bgWhite`
- `bgBlackBright` (alias: `bgGray`, `bgGrey`)
- `bgRedBright`
- `bgGreenBright`
- `bgYellowBright`
- `bgBlueBright`
- `bgMagentaBright`
- `bgCyanBright`
- `bgWhiteBright`

## 256 and Truecolor color support

Chalk supports 256 colors and [Truecolor](https://gist.github.com/XVilka/8346728) (16 million colors) on supported terminal apps.

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).

Examples:

- `chalk.hex('#DEADED').underline('Hello, world!')`
- `chalk.rgb(15, 100, 204).inverse('Hello!')`

Background versions of these models are prefixed with `bg` and the first level of the module capitalized (e.g. `hex` for foreground colors and `bgHex` for background colors).

- `chalk.bgHex('#DEADED').underline('Hello, world!')`
- `chalk.bgRgb(15, 100, 204).inverse('Hello!')`

The following color models can be used:

- [`rgb`](https://en.wikipedia.org/wiki/RGB_color_model) - Example: `chalk.rgb(255, 136, 0).bold('Orange!')`
- [`hex`](https://en.wikipedia.org/wiki/Web_colors#Hex_triplet) - Example: `chalk.hex('#FF8800').bold('Orange!')`
- [`ansi256`](https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit) - Example: `chalk.bgAnsi256(194)('Honeydew, more or less')`

## Browser support

Since Chrome 69, ANSI escape codes are natively supported in the developer console.

## Windows

If you're on Windows, do yourself a favor and use [Windows Terminal](https://github.com/microsoft/terminal) instead of `cmd.exe`.

## Origin story

[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.

## Related

- [chalk-template](https://github.com/chalk/chalk-template) - [Tagged template literals](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals#tagged_templates) support for this module
- [chalk-cli](https://github.com/chalk/chalk-cli) - CLI for this module
- [ansi-styles](https://github.com/chalk/ansi-styles) - ANSI escape codes for styling strings in the terminal
- [supports-color](https://github.com/chalk/supports-color) - Detect whether a terminal supports color
- [strip-ansi](https://github.com/chalk/strip-ansi) - Strip ANSI escape codes
- [strip-ansi-stream](https://github.com/chalk/strip-ansi-stream) - Strip ANSI escape codes from a stream
- [has-ansi](https://github.com/chalk/has-ansi) - Check if a string has ANSI escape codes
- [ansi-regex](https://github.com/chalk/ansi-regex) - Regular expression for matching ANSI escape codes
- [wrap-ansi](https://github.com/chalk/wrap-ansi) - Wordwrap a string with ANSI escape codes
- [slice-ansi](https://github.com/chalk/slice-ansi) - Slice a string with ANSI escape codes
- [color-convert](https://github.com/qix-/color-convert) - Converts colors between different models
- [chalk-animation](https://github.com/bokub/chalk-animation) - Animate strings in the terminal
- [gradient-string](https://github.com/bokub/gradient-string) - Apply color gradients to strings
- [chalk-pipe](https://github.com/LitoMore/chalk-pipe) - Create chalk style schemes with simpler style strings
- [terminal-link](https://github.com/sindresorhus/terminal-link) - Create clickable links in the terminal

## Maintainers

- [Sindre Sorhus](https://github.com/sindresorhus)
- [Josh Junon](https://github.com/qix-)