kleur
Advanced tools
Package description
The kleur npm package is a library for formatting terminal text with ANSI colors. It provides a simple and chainable API to style strings that are output to the console with various colors, backgrounds, and text styles.
Coloring text
This feature allows you to apply text color to your console output. The example shows how to color the text green.
const kleur = require('kleur');
console.log(kleur.green('Hello world!'));Chaining styles
Kleur supports chaining multiple styles together. In this example, the text 'Error!' is styled to be red, bold, and underlined.
const kleur = require('kleur');
console.log(kleur.red().bold().underline('Error!'));Background colors
You can also set background colors for your text. Here, the text 'Info' has a blue background with white foreground color.
const kleur = require('kleur');
console.log(kleur.bgBlue().white('Info'));Conditional styling
Kleur allows conditional styling, where you can enable or disable colors based on certain conditions. In this example, the red color is applied only if the environment is not production.
const kleur = require('kleur');
const enabled = process.env.NODE_ENV !== 'production';
console.log(kleur.enabled(enabled).red('Only styled if not in production'));Chalk is a popular npm package similar to kleur that allows for styling terminal strings. It offers a more extensive API and additional features like template literal support and custom themes, but it is slightly larger in size compared to kleur.
Colors is another package that provides ANSI color formatting for text in the terminal. It extends String.prototype to add color properties, which some developers may find less clean than the functional approach taken by kleur.
Ansi-colors is a lightweight package that focuses on performance. Like kleur, it does not extend String.prototype and has a chainable API, but it has fewer dependencies and is designed to be as minimal as possible.
Readme
String.prototype modificationsAs of v3.0 the Chalk-style syntax (magical getter) is no longer used.
If you need or require that syntax, consider using ansi-colors, which maintains chalk parity.
$ npm install --save kleur
const { red, white, blue, bold } = require('kleur');
// basic usage
red('red text');
// chained methods
blue().bold().underline('howdy partner');
// nested methods
bold(`${ white().bgRed('[ERROR]') } ${ red().italic('Something happened')}`);
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'));
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'));
Toggle color support as needed; kleur includes simple auto-detection which may not cover all cases.
const kleur = require('kleur');
// manually disable
kleur.enabled = false;
// or use another library to detect support
kleur.enabled = require('color-support').level;
console.log(kleur.red('I will only be colored red if the terminal supports 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.
Colors:
black — red — green — yellow — blue — magenta — cyan — white — gray — grey
Backgrounds:
bgBlack — bgRed — bgGreen — bgYellow — bgBlue — bgMagenta — bgCyan — bgWhite
Modifiers:
reset — bold — dim — italic* — underline — inverse — hidden — strikethrough*
* Not widely supported
Using Node v10.13.0
chalk :: 14.543ms
kleur :: 0.474ms
ansi-colors :: 1.923ms
# All Colors
ansi-colors x 199,381 ops/sec ±1.04% (96 runs sampled)
chalk x 12,107 ops/sec ±2.07% (87 runs sampled)
kleur x 715,334 ops/sec ±0.30% (93 runs sampled)
# Stacked colors
ansi-colors x 24,494 ops/sec ±1.03% (93 runs sampled)
chalk x 2,650 ops/sec ±2.06% (85 runs sampled)
kleur x 75,798 ops/sec ±0.19% (97 runs sampled)
# Nested colors
ansi-colors x 77,766 ops/sec ±0.32% (94 runs sampled)
chalk x 5,596 ops/sec ±1.85% (86 runs sampled)
kleur x 137,660 ops/sec ±0.31% (93 runs sampled)
This project originally forked Brian Woodward's awesome ansi-colors library.
Beginning with kleur@3.0, the Chalk-style syntax (magical getter) has been replaced with function calls per key:
// Old:
c.red.bold.underline('old');
// New:
c.red().bold().underline('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. Versions below kleur@3.0 have been deprecated.
MIT © Luke Edwards
FAQs
The fastest Node.js library for formatting terminal text with ANSI colors~!
We found that kleur demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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