Awesome

Colorize terminal with ANSI colors & styles, smaller and faster alternative to Chalk with additional useful features.

🚀 Install and Quick Start

Usage

import ansis, { red, green, cyan, black, ansi256, hex } from 'ansis';

ansis.blueBright('file.txt')
green`Succeful!`
red`Error: ${cyan(file)} not found!`
black.bgYellow`Warning!`
ansi256(214)`Orange`
hex('#E0115F').bold.underline('TrueColor!')

<a id="top" name="top"></a>

👀 Why yet one lib?

• Quality is first, test coverage 100%.
• Ansis has all features that you need, compare with other libraries.
• Ansis is one of the smallest, 3.5 KB only.
• Ansis is one of the fastest, up to x3 faster than Chalk, see benchmarks.
• Ansis is stable, continuously developing and improving.
• Ansis is open for your feature requests.
• Quick response to issues.
• Long term support.

⚖️ Similar packages

Most popular ANSI libraries for Node.js:

chalk, kleur, ansi-colors, kolorist, colorette, picocolors, cli-color, colors-cli, colors.js

• ✅ Compare features
• 💾 Compare package sizes
• 📊 Benchmarks

<a id="features" name="features"></a>

💡 Highlights

• Supports both ESM and CommonJS
• Supports TypeScript
• Supports Bun, Deno, Next.JS runtimes
• Standard API, drop-in replacement for Chalk

  - import chalk from 'chalk';
  + import chalk, { red } from 'ansis';
  

  chalk.red.bold('Error!'); // <- Chalk like syntax works fine with Ansis
  red.bold('Error!');       // <- the same result with Ansis
  red.bold`Error!`;         // <- the same result with Ansis
  

• Default and named import import ansis, { red, bold, ansi256, hex } from 'ansis'
• Chained syntax red.bold.underline('text')
• Nested template strings red`RED ${green`GREEN`} RED`
• ANSI styles dim bold italic <u>underline</u> <s>strikethrough</s>
• ANSI 16 colors red`Error!` redBright`Error!` bgRed`Error!` bgRedBright`Error!`
• ANSI 256 colors fg(56)`violet` bg(208)`orange`
• TrueColor (RGB, HEX) rgb(224, 17, 95)`Ruby` hex('#96C')`Amethyst`
• Fallback to supported color space: TrueColor → 256 colors → 16 colors → no colors
• Extending of base colors with named True Colors
• Raw ANSI codes as open and close properties `foo ${red.open}red{red.close} bar`
• Strip ANSI codes method ansis.strip()
• Detect color support using ansis.isSupported() method
• Supports environment variables NO_COLOR FORCE_COLOR and flags --no-color --color
• Correct style break at the end of line when used \n in string
• Doesn't extend String.prototype
• Zero dependencies

🔆 What's New in v3

• NEW added detection of supported color space: TrueColor, 256 colors, 16 colors, no colors (black & white)
• NEW added fallback to supported color space: TrueColor —> 256 colors —> 16 colors —> no colors

⚠️ Warning

The v3 has the BREAKING CHANGES (removed not widely supported styles and DEPRECATIONS).
For details see the changelog.

❓Question / Feature Request / Bug

If you have discovered a bug or have a feature suggestion, feel free to create an issue on GitHub.

<a id="install" name="install"></a>

Install and Quick Start

npm install ansis

You can import default module or named colors with ESM or CommonJS syntax.

// ESM default import
import ansis from 'ansis';
// ESM named import
import { red, green, blue } from 'ansis';

or

// CommonJS default import
const ansis = require('ansis');
// CommonJS named import
const { red, green, blue } = require('ansis');

See the list of the ANSI colors and styles.

console.log(ansis.green('Success!'));
console.log(green('Success!'));

// template string
console.log(green`Success!`);

// chained syntax
console.log(green.bold`Success!`);

// nested syntax
console.log(red`The ${blue.underline`file.js`} not found!`);

Basic example Hello World!:

import { red, black, inverse, reset } from 'ansis';

console.log(green`Hello ${inverse`ANSI`} World!
${black.bgYellow`Warning:`} ${cyan`/path/to/file.js`} ${red`not found!`}`);

Output:

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<a id="named-import" name="named-import"></a>

Named import

The ansis supports both the default import and named import.

// default import
import ansis from 'ansis';

ansis.red.bold('text');

You can import named colors, styles and functions. All imported colors and styles are chainable.

// named import
import { red, hex, italic } from 'ansis';

red.bold('text');

Default import and named import can be combined.

// default and named import
import ansis, { red } from 'ansis';

const redText = red('text'); // colorized ANSI string
const text = ansis.strip(redText); // pure string without ANSI codes

<a id="template-literals" name="template-literals"></a>

Template literals

The ansis supports both the function syntax red('error') and template literals red`error`.

The template literals allow you to make a complex template more readable and shorter.
The function syntax can be used to colorize a variable.

import { red } from 'ansis';

let message = 'error';

red(message);
red`text`;
red`text ${message} text`;

<a id="chained-syntax" name="chained-syntax"></a>

Chained syntax

All colors, styles and functions are chainable. Each color or style can be combined in any order.

import { red, bold, italic, hex } from 'ansis';

red.bold`text`;
hex('#FF75D1').bgCyan.bold`text`;
bold.bgHex('#FF75D1').cyan`text`;
italic.bold.yellow.bgMagentaBright`text`;

<a id="nested-syntax" name="nested-syntax"></a>

Nested syntax

You can nest functions and template strings within each other. None of the other libraries (chalk, kleur, colorette, colors.js etc.) support nested template strings.

Nested template strings:

import { red, green } from 'ansis';

red`red ${green`green`} red`;

Deep nested chained styles:

import { red, green, cyan, magenta, yellow, italic, underline } from 'ansis';

red(`red ${italic(`red italic ${underline(`red italic underline`)}`)} red`);

// deep nested chained styles
green(
  `green ${yellow(
    `yellow ${magenta(
      `magenta ${cyan(
        `cyan ${red.italic.underline`red italic underline`} cyan`,
      )} magenta`,
    )} yellow`,
  )} green`,
);

Output:

Multiline nested template strings:

import { red, green, hex, visible, inverse } from 'ansis';

// defined a TrueColor as the constant
const orange = hex('#FFAB40');

let cpu = 33;
let ram = 44;
let disk = 55;

// normal colors
visible`
CPU:  ${red`${cpu}%`}
RAM:  ${green`${ram}%`}
DISK: ${orange`${disk}%`}
`;

// inversed colors
inverse`
CPU:  ${red`${cpu}%`}
RAM:  ${green`${ram}%`}
DISK: ${orange`${disk}%`}
`;

Output:

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<a id="base-colors" name="base-colors"></a>

Base ANSI 16 colors and styles

Colors and styles have standard names used by many popular libraries, such as chalk, colorette, kleur.

<a id="extend-colors" name="extend-colors"></a>

Extend base colors

Defaults, the imported ansis instance contains base styles and colors. To extend base colors with custom color names for TrueColor use the ansis.extend() method.

import ansis from 'ansis';

// extend base colors
ansis.extend({
  pink: '#FF75D1',
  orange: '#FFAB40',
});

// the custom colors are available under namespace `ansis`
ansis.pink('text');
ansis.orange('text');

Usage example with TypeScript:

import ansis, { AnsiColorsExtend } from 'ansis';

// extend base colors
ansis.extend({
  pink: '#FF75D1',
  orange: '#FFAB40',
});

const write = (style: AnsiColorsExtend<'pink' | 'orange'>, message: string) => {
  console.log(ansis[style](message));
}

write('red', 'message'); // base color OK
write('pink', 'message'); // extended color OK
write('orange', 'message'); // extended color OK
write('unknown', 'message'); // TypeScript Error

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<a id="256-colors" name="256-colors"></a>

ANSI 256 colors

The pre-defined set of 256 colors.

Foreground function: ansi256(code) has short alias fg(code)
Background function: bgAnsi256(code) has short alias bg(code)

The ansi256() and bgAnsi256() methods are implemented for compatibility with the chalk API.

See ANSI color codes.

Fallback

If a terminal supports only 16 colors then ANSI 256 colors will be interpolated into base 16 colors.

Usage example

import { bold, ansi256, fg, bgAnsi256, bg } from 'ansis';

// foreground color
ansi256(96)`Bright Cyan`;
fg(96)`Bright Cyan`; // alias for ansi256

// background color
bgAnsi256(105)`Bright Magenta`;
bg(105)`Bright Magenta`; // alias for bgAnsi256

// function is chainable
ansi256(96).bold`bold Bright Cyan`;

// function is avaliable in each style
bold.ansi256(96).underline`bold underline Bright Cyan`;

// you can combine the functions and styles in any order
bgAnsi256(105).ansi256(96)`cyan text on magenta background`
bg(105).fg(96)`cyan text on magenta background`

<a id="truecolor" name="truecolor"></a>

TrueColor

You can use the hex or rgb format.

Foreground function: hex() rgb()
Background function: bgHex() bgRgb()

import { bold, hex, rgb, bgHex, bgRgb } from 'ansis';

// foreground color
hex('#E0115F').bold`bold Ruby`;
hex('#96C')`Amethyst`;
rgb(224, 17, 95).italic`italic Ruby`;

// background color
bgHex('#E0115F')`Ruby`;
bgHex('#96C')`Amethyst`;
bgRgb(224, 17, 95)`Ruby`;

// you can combine the functions and styles in any order
bold.hex('#E0115F').bgHex('#96C')`ruby bold text on amethyst background`

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<a id="fallback" name="fallback"></a>

Fallback

The ansis supports fallback to supported color space.

TrueColor —> 256 colors —> 16 colors —> no colors (black & white)

If you use the hex(), rgb() or ansis256() functions in a terminal not supported TrueColor or 256 colors, then colors will be interpolated.

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<a id="escape-codes" name="escape-codes"></a>

Use ANSI codes

You can use the ANSI escape codes with open and close properties for each style.

import { red, bold } from 'ansis';

// each style has `open` and `close` properties
console.log(`Hello ${red.open}ANSI${red.close} World!`);

// you can defiene own style which will have the `open` and `close` properties
const myStyle = bold.italic.black.bgHex('#E0115F');

console.log(`Hello ${myStyle.open}ANSI${myStyle.close} World!`);

<a id="strip" name="strip"></a>

Strip ANSI codes

The Ansis class contains the method strip() to remove all ANSI codes from string.

import ansis from 'ansis';

const ansiString = ansis.green`Hello World!`;
const string = ansis.strip(ansiString);

The variable string will contain the pure string without ANSI codes.

<a id="new-line" name="new-line"></a>

New lines

Supports correct style break at the end of line.

import { bgGreen } from 'ansis';

console.log(bgGreen`\nAnsis\nNew Line\nNext New Line\n`);

<a id="shortcuts" name="shortcuts"></a>

Shortcuts / Themes

Define your own themes:

import ansis from 'ansis';

const theme = {
  info: ansis.cyan.italic,
  warn: ansis.black.bgYellowBright,
  error: ansis.red.bold,
  ruby: ansis.hex('#E0115F'),
};

theme.info('info');
theme.warn('warning');
theme.error('error');
theme.ruby('Ruby color');

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<a id="cli-vars" name="cli-vars"></a>

CLI

Defaults, the output in terminal console is colored and output in a file is uncolored.

Environment variables

To force disable or enable colored output use environment variables NO_COLOR and FORCE_COLOR.

The NO_COLOR variable should be presents with any not empty value. The value is not important, e.g., NO_COLOR=1 NO_COLOR=true disable colors.
See standard description by NO_COLOR.

The FORCE_COLOR variable should be presents with one of values:
FORCE_COLOR=0 force disable colors
FORCE_COLOR=1 force enable colors
See standard description by FORCE_COLOR.

For example, app.js:

import { red } from 'ansis';

console.log(red`red color`);

Execute the script in a terminal:

$ node app.js           # colored output in terminal
$ node app.js > log.txt # output in file without ANSI codes

$ NO_COLOR=1 node app.js              # force disable colors, non colored output in terminal
$ FORCE_COLOR=0 node app.js           # force disable colors, non colored output in terminal
$ FORCE_COLOR=1 node app.js > log.txt # force enable colors, output in file with ANSI codes

How to force enable 256 colors

If your environment supports 256 colors, but ansis detects only 16 or mono, you can manually set the TERM variable with standard values: screen-256color or xterm-256color.

You can set the variable in CLI:

TERM=screen-256color node script.js

or directly in your script:

process.env.TERM = 'screen-256color';

How to force enable truecolor

If your environment supports truecolor, but ansis detects only 256, 16 or mono, you can manually set the COLORTERM variable with standard values: truecolor or 24bit.

You can set the variable in CLI:

COLORTERM=truecolor node script.js

or directly in your script:

process.env.COLORTERM = 'truecolor';

CLI arguments

Use arguments --no-color or --color=false to disable colors and --color to enable ones.

For example, an executable script app.js:

#!/usr/bin/env node
import { red } from 'ansis';

console.log(red`red color`);

Execute the script in a terminal:

$ ./app.js                        # colored output in terminal
$ ./app.js --no-color             # non colored output in terminal
$ ./app.js --color=false          # non colored output in terminal

$ ./app.js > log.txt              # output in file without ANSI codes
$ ./app.js --color > log.txt      # output in file with ANSI codes
$ ./app.js --color=true > log.txt # output in file with ANSI codes

Warning

The command line arguments have a higher priority than environment variable.

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<a id="color-support" name="color-support"></a>

Color support

Ansis automatically detects the supported color space:

• TrueColor
• ANSI 256 colors
• ANSI 16 colors
• black & white (no colors)

Ansis has the method isSupported() that returns a boolean value whether the output supports ANSI color and styles.

import ansis from 'ansis';

console.log('Color output: ', ansis.isSupported());

There is no standard way to detect which color space is supported. The most common way to detect color support is to check the TERM and COLORTERM environment variables. CI systems can be detected by checking for the existence of the CI and other specifically environment variables. Combine that with the knowledge about which operating system the program is running on, and we have a decent enough way to detect colors.

See also:

• Truecolor Support in Output Devices.
• So you want to render colors in your terminal.

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<a id="compare" name="compare"></a>

Compare the features of most popular libraries

Run the command to see the support of some features by various libraries:

npm run compare

Note

Named import
ESM
import { red, green, blue } from 'lib';
CJS
const { red, green, blue } = require('lib');

Naming colors

• standard: colors have standard names, e.g.: red, redBright, bgRed, bgRedBright
• non-standard: colors have lib-specific names, e.g.: brightRed, bgBrightRed, red_b, red_btt

ANSI 256 colors

The method names:

• colors-cli: x<n>
• cli-color: xterm(n)
• chalk: ansi256(n) bgAnsi256(n)
• ansis: ansi256(n) bgAnsi256(n) fg(n) bg(n)

TrueColor

The method names:

• chalk: hex() rgb()
• ansis: hex() rgb()

Chained syntax
lib.red.bold('text')

Nested template strings
lib.red`text ${lib.cyan`nested`} text`

New line
Correct break styles at end-of-line.

lib.bgGreen(`First Line
Next Line`);

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<a id="compare-size" name="compare-size"></a>

Compare the size of most popular packages

Require size: The size of distributed code that will be loaded via require or import into your app.
Install size: The unpacked size of the npm package in the node_modules/ directory, (incl. dependencies).
Download size: The gzipped size of the npm package.

See also:

• npmjs - show install size of the published package, w/o dependencies
• packagephobia - show total install size, incl. dependencies
• npm download size - show tarball and total download size
• bundlephobia - useless, doesn't show real tarball size of the downloaded npm package

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Show ANSI demo

git clone https://github.com/webdiscus/ansis.git
cd ./ansis
npm i
npm run demo

<a id="benchmark" name="#benchmark"></a>

Benchmarks

To measure performance is used benchmark.js.

‼️ Warning

Don't trust other test results using vitest benchmark.

The vitest benchmark generate FALSE/unreal results.
For example, the results of the simple bench:

chalk.red('foo') -  7.000.000 ops/sec
ansis.red('foo') - 23.000.000 ops/sec (x3 faster is WRONG result)

The real performance results of chalk and ansis in this test are very close.

Run benchmarks

git clone https://github.com/webdiscus/ansis.git
cd ./ansis
npm i
npm run bench

Tested on

MacBook Pro 16" M1 Max 64GB
macOS Monterey 12.1
Node.js v16.13.1
Terminal iTerm2

Colorette bench

The benchmark used in colorette.

c.red(`${c.bold(`${c.cyan(`${c.yellow('yellow')}cyan`)}`)}red`);

+  colorette           4,572,582 ops/sec   very fast
   picocolors          3,841,124 ops/sec   very fast
-> ansis               2,725,758 ops/sec   fast
   chalk               2,287,146 ops/sec   fast
   kleur/colors        2,281,415 ops/sec   fast
   kleur               2,228,639 ops/sec   fast
   ansi-colors         1,265,615 ops/sec   slow
   colors.js           1,158,572 ops/sec   slow
   cli-color             470,320 ops/sec   too slow
   colors-cli            109,811 ops/sec   too slow

Base colors

const colors = ['black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'white'];
colors.forEach((color) => c[color]('foo'));

+  picocolors          8,265,628 ops/sec  very fast
-> ansis               6,197,754 ops/sec  fast
   kleur               5,455,121 ops/sec  fast
   chalk               4,428,884 ops/sec  fast
   kleur/colors        2,074,111 ops/sec  slow
   colorette           1,874,506 ops/sec  slow
   ansi-colors         1,010,628 ops/sec  slow
   colors.js             640,101 ops/sec  too slow
   cli-color             305,690 ops/sec  too slow
   colors-cli            104,962 ops/sec  too slow

Chained styles

const colors = ['black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'white'];
colors.forEach((color) => c[color].bold.underline.italic('foo'));

+  ansis               5,515,868 ops/sec  very fast
   chalk               1,234,573 ops/sec  fast
   kleur                 514,035 ops/sec  slow
   ansi-colors           158,921 ops/sec  too slow
   cli-color             144,837 ops/sec  too slow
   colors.js             138,219 ops/sec  too slow
   colors-cli             52,732 ops/sec  too slow
   kleur/colors        (not supported)
   colorette           (not supported)
   picocolors          (not supported)

Nested calls

const colors = ['black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'white'];
colors.forEach((color) => c[color](c.bold(c.underline(c.italic('foo')))));

+  picocolors            942,592 ops/sec  very fast
   colorette             695,350 ops/sec  fast
   kleur                 648,195 ops/sec  fast
   kleur/colors          561,111 ops/sec  fast
-> ansis                 558,575 ops/sec  fast
   chalk                 497,292 ops/sec  fast
   ansi-colors           260,316 ops/sec  slow
   colors.js             166,425 ops/sec  slow
   cli-color              65,561 ops/sec  too slow
   colors-cli             13,800 ops/sec  too slow

Nested styles

c.red(
  `a red ${c.white('white')} red ${c.red('red')} red ${c.cyan('cyan')} red ${c.black('black')} red ${c.red('red')} red
  ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red
  ${c.green('green')} red ${c.red('red')} red ${c.yellow('yellow')} red ${c.blue('blue')} red ${c.red('red')} red
  ${c.magenta('magenta')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red
  ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red
  ${c.black('black')} red ${c.yellow('yellow')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red
  ${c.yellow('yellow')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red
  ${c.green('green')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red
  ${c.magenta('magenta')} red ${c.red('red')} red ${c.red('red')} red ${c.cyan('cyan')} red ${c.red('red')} red
  ${c.cyan('cyan')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red ${c.red('red')} red message`
);

+  picocolors            243,975 ops/sec  very fast
   colorette             243,139 ops/sec  very fast
   kleur/colors          234,132 ops/sec  very fast
   kleur                 221,446 ops/sec  very fast
-> ansis                 211,868 ops/sec  very fast
   chalk                 189,960 ops/sec  fast
   ansi-colors           121,451 ops/sec  slow
   colors.js              89,633 ops/sec  too slow
   cli-color              41,657 ops/sec  too slow
   colors-cli             14,264 ops/sec  too slow

Deep nested styles

c.green(
  `green ${c.cyan(
    `cyan ${c.red(
      `red ${c.yellow(
        `yellow ${c.blue(
          `blue ${c.magenta(`magenta ${c.underline(`underline ${c.italic(`italic`)} underline`)} magenta`)} blue`
        )} yellow`
      )} red`
    )} cyan`
  )} green`
);

+  colorette           1,131,757 ops/sec  very fast
   picocolors          1,002,649 ops/sec  very fast
-> ansis                 882,220 ops/sec  very fast
   chalk                 565,965 ops/sec  fast
   kleur/colors          478,547 ops/sec  fast
   kleur                 464,004 ops/sec  fast
   colors.js             451,592 ops/sec  fast
   ansi-colors           362,733 ops/sec  slow
   cli-color             213,441 ops/sec  slow
   colors-cli             40,340 ops/sec  too slow

HEX colors

Only two libraries support TrueColor: ansis and chalk

c.hex('#FBA')('foo');

+  ansis               4,944,572 ops/sec  very fast
   chalk               2,891,684 ops/sec  fast
   colors.js           (not supported)
   colorette           (not supported)
   picocolors          (not supported)
   cli-color           (not supported)
   colors-cli          (not supported)
   ansi-colors         (not supported)
   kleur/colors        (not supported)
   kleur               (not supported)

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Testing

npm run test will run the unit and integration tests.
npm run test:coverage will run the tests with coverage.

License

ISC