Terminal string styling done right

• Why not switch to a smaller coloring package?
• Seeyoctocolors for a smaller alternative

• Expressive API
• Highly performant
• No dependencies
• Ability to nest styles
• 256/Truecolor color support
• Auto-detects color support
• Doesn't extendString.prototype
• Clean and focused
• Actively maintained
• Used by ~115,000 packages as of July 4, 2024

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.

importchalkfrom'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.

importchalkfrom'chalk';constlog=console.log;// Combine styled and normal stringslog(chalk.blue('Hello')+' World'+chalk.red('!'));// Compose multiple styles using the chainable APIlog(chalk.blue.bgRed.bold('Hello world!'));// Pass in multiple argumentslog(chalk.blue('Hello','World!','Foo','bar','biz','baz'));// Nest styleslog(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 literallog(`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:

importchalkfrom'chalk';consterror=chalk.bold.red;constwarning=chalk.hex('#FFA500');// Orange colorconsole.log(error('Error!'));console.log(warning('Warning!'));

Take advantage of console.logstring substitution:

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

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

Chainstyles 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 thatchalk.red.yellow.green is equivalent tochalk.green.

Multiple arguments will be separated by space.

Specifies the level of color support.

Color support is automatically detected, but you can override it by setting thelevel 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:

import{Chalk}from'chalk';constcustomChalk=newChalk({level:0});

Detect whether the terminalsupports 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 variableFORCE_COLOR=1 (level 1),FORCE_COLOR=2 (level 2), orFORCE_COLOR=3 (level 3) to forcefully enable color, orFORCE_COLOR=0 to forcefully disable. The use ofFORCE_COLOR overrides all other color support checks.

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

chalkStderr contains a separate instance configured with color support detected forstderr stream instead ofstdout. Override rules fromsupportsColor apply to this too.supportsColorStderr is exposed for convenience.

All supported style strings are exposed as an array of strings for convenience.colorNames is the combination offoregroundColorNames andbackgroundColorNames.

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

import{modifierNames,foregroundColorNames}from'chalk';console.log(modifierNames.includes('bold'));//=> trueconsole.log(foregroundColorNames.includes('pink'));//=> false

• 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.

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

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

Chalk supports 256 colors andTruecolor (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 withbg and the first level of the module capitalized (e.g.hex for foreground colors andbgHex for background colors).

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

The following color models can be used:

• rgb - Example:chalk.rgb(255, 136, 0).bold('Orange!')
• hex - Example:chalk.hex('#FF8800').bold('Orange!')
• ansi256 - Example:chalk.bgAnsi256(194)('Honeydew, more or less')

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

If you're on Windows, do yourself a favor and useWindows Terminal instead ofcmd.exe.

Chalk may be larger, but there is a reason for that. It offers a more user-friendly API, well-documented types, supports millions of colors, and covers edge cases that smaller alternatives miss. Chalk is mature, reliable, and built to last.

But beyond the technical aspects, there's something more critical: trust and long-term maintenance. I have been active in open source for over a decade, and I'm committed to keeping Chalk maintained. Smaller packages might seem appealing now, but there's no guarantee they will be around for the long term, or that they won't become malicious over time.

Chalk is also likely already in your dependency tree (since 100K+ packages depend on it), so switching won’t save space—in fact, it might increase it. npm deduplicates dependencies, so multiple Chalk instances turn into one, but adding another package alongside it will increase your overall size.

If the goal is to clean up the ecosystem, switching away from Chalk won’t even make a dent. The real problem lies with packages that have very deep dependency trees (for example, those including a lot of polyfills). Chalk has no dependencies. It's better to focus on impactful changes rather than minor optimizations.

If absolute package size is important to you, I also maintainyoctocolors, one of the smallest color packages out there.

-Sindre

Micro-benchmarks are flawed because they measure performance in unrealistic, isolated scenarios, often giving a distorted view of real-world performance. Don't believe marketing fluff. All the coloring packages are more than fast enough.

• chalk-template -Tagged template literals support for this module
• chalk-cli - CLI for this module
• ansi-styles - ANSI escape codes for styling strings in the terminal
• supports-color - Detect whether a terminal supports color
• strip-ansi - Strip ANSI escape codes
• strip-ansi-stream - Strip ANSI escape codes from a stream
• has-ansi - Check if a string has ANSI escape codes
• ansi-regex - Regular expression for matching ANSI escape codes
• wrap-ansi - Wordwrap a string with ANSI escape codes
• slice-ansi - Slice a string with ANSI escape codes
• color-convert - Converts colors between different models
• chalk-animation - Animate strings in the terminal
• gradient-string - Apply color gradients to strings
• chalk-pipe - Create chalk style schemes with simpler style strings
• terminal-link - Create clickable links in the terminal

(Not accepting additional entries)

• Sindre Sorhus
• Josh Junon