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The fastest Node.js library for formatting terminal text with ANSI colors~!


Version published
Weekly downloads
decreased by-2.47%

Weekly downloads





  • Add "types" export conditions for Node16 TypeScript module resolution (#57): 06f28e0 Thank you @calebeby~!
  • Handle undefined process.env with fallback (#54): ec20016 For browser/vite support. Thank you @farnabaz~!

Full Changelog:


version CI downloads install size
The fastest Node.js library for formatting terminal text with ANSI colors~!


As of v3.0 the Chalk-style syntax (magical getter) is no longer used.
Please visit History for migration paths supporting that syntax.


$ npm install --save kleur


import kleur from 'kleur'; // basic usage'red text'); // chained methods'howdy partner'); // nested methods kleur.bold(`${ white().bgRed('[ERROR]') } ${'Something happened')}`);

Chained Methods

const { bold, green } = require('kleur'); console.log(bold().red('this is a bold red message')); console.log(bold().italic('this is a bold italicized message')); console.log(bold().yellow().bgRed().italic('this is a bold yellow italicized message')); console.log(green().bold().underline('this is a bold green underlined message'));

Nested Methods

const { yellow, red, cyan } = require('kleur'); console.log(yellow(`foo ${red().bold('red')} bar ${cyan('cyan')} baz`)); console.log(yellow('foo ' + red().bold('red') + ' bar ' + cyan('cyan') + ' baz'));

Conditional Support

Toggle color support as needed; kleur includes simple auto-detection which may not cover all cases.

Note: Both kleur and kleur/colors share the same detection logic.

import kleur from 'kleur'; // manually disable kleur.enabled = false; // or use another library to detect support kleur.enabled = require('color-support').level > 0; console.log('I will only be colored red if the terminal supports colors'));

Colors will be disabled automatically in non TTY contexts. For example, spawning another process or piping output into another process will disable colorization automatically. To force colors in your piped output, you may do so with the FORCE_COLOR=1 environment variable:

$ node app.js #=> COLORS $ node app.js > log.txt #=> NO COLORS $ FORCE_COLOR=1 node app.js > log.txt #=> COLORS $ FORCE_COLOR=0 node app.js > log.txt #=> NO COLORS


Any kleur method returns a String when invoked with input; otherwise chaining is expected.

It's up to the developer to pass the output to destinations like console.log, process.stdout.write, etc.

The methods below are grouped by type for legibility purposes only. They each can be chained or nested with one another.


black — red — green — yellow — blue — magenta — cyan — white — gray — grey


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


reset — bold — dim — italic* — underline — inverse — hidden — strikethrough*

* Not widely supported

Individual Colors

When you only need a few colors, it doesn't make sense to import all of kleur because, as small as it is, kleur is not treeshakeable, and so most of its code will be doing nothing. In order to fix this, you can import from the kleur/colors submodule which fully supports tree-shaking.

The caveat with this approach is that color functions are not chainable~!
Each function receives and colorizes its input. You may combine colors, backgrounds, and modifiers by nesting function calls within other functions.

// or: import * as kleur from 'kleur/colors'; import { red, underline, bgWhite } from 'kleur/colors'; red('red text'); //~>'red text'); underline(red('red underlined text')); //~> kleur.underline().red('red underlined text'); bgWhite(underline(red('red underlined text w/ white background'))); //~> kleur.bgWhite().underline().red('red underlined text w/ white background');

Note: All the same colors, backgrounds, and modifiers are available.

Conditional Support

The kleur/colors submodule also allows you to toggle color support, as needed.
It includes the same initial assumptions as kleur, in an attempt to have colors enabled by default.

Unlike kleur, this setting exists as kleur.$.enabled instead of kleur.enabled:

import * as kleur from 'kleur/colors'; // or: import { $, red } from 'kleur/colors'; // manually disabled kleur.$.enabled = false; // or use another library to detect support kleur.$.enabled = require('color-support').level > 0; console.log(red('I will only be colored red if the terminal supports colors'));


Using Node v10.13.0

Load time

chalk :: 5.303ms kleur :: 0.488ms kleur/colors :: 0.369ms ansi-colors :: 1.504ms


# All Colors ansi-colors x 177,625 ops/sec ±1.47% (92 runs sampled) chalk x 611,907 ops/sec ±0.20% (92 runs sampled) kleur x 742,509 ops/sec ±1.47% (93 runs sampled) kleur/colors x 881,742 ops/sec ±0.19% (98 runs sampled) # Stacked colors ansi-colors x 23,331 ops/sec ±1.81% (94 runs sampled) chalk x 337,178 ops/sec ±0.20% (98 runs sampled) kleur x 78,299 ops/sec ±1.01% (97 runs sampled) kleur/colors x 104,431 ops/sec ±0.22% (97 runs sampled) # Nested colors ansi-colors x 67,181 ops/sec ±1.15% (92 runs sampled) chalk x 116,361 ops/sec ±0.63% (94 runs sampled) kleur x 139,514 ops/sec ±0.76% (95 runs sampled) kleur/colors x 145,716 ops/sec ±0.97% (97 runs sampled)


This project originally forked ansi-colors.

Beginning with [email protected], the Chalk-style syntax (magical getter) has been replaced with function calls per key:

// Old:'old'); // New:'new');

As I work more with Rust, the newer syntax feels so much better & more natural!

If you prefer the old syntax, you may migrate to ansi-colors or newer chalk releases.
Versions below [email protected] have been officially deprecated.


MIT © Luke Edwards



What is kleur?

The fastest Node.js library for formatting terminal text with ANSI colors~!

Is kleur popular?

The npm package kleur receives a total of 14,900,927 weekly downloads. As such, kleur popularity was classified as popular.

Is kleur well maintained?

We found that kleur demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago.It has 1 open source maintainer collaborating on the project.

Last updated on 26 Jun 2022


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