# wcag-contrast > evaluate the wcag color contrast score for two colors Latest version **3.0.0** (published 2019-11-05) · BSD-2-Clause license · 0 weekly downloads ## Install ```sh npm install wcag-contrast pnpm add wcag-contrast yarn add wcag-contrast bun add wcag-contrast ``` ## Health **Score 28/100 (F)** — status: abandoned. Positive: has types package; esm support; no vulnerabilities; high quality score. Warnings: low downloads. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 3.0.0 | | Published | 2019-11-05 | | First published | 2013-09-24 | | Weekly downloads | 0 | | License | BSD-2-Clause | | TypeScript types | separate (@types/wcag-contrast) | | Module format | ESM + CommonJS | | Dependencies | 1 | | Unpacked size | 24.4 KB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 130 | | Author | Tom MacWright | | Maintainers | tmcw | | Keywords | color, contrast, wcag | ## Links - npm: https://www.npmjs.com/package/wcag-contrast - Repository: https://github.com/tmcw/wcag-contrast - Homepage: https://github.com/tmcw/wcag-contrast#readme - Issues: https://github.com/tmcw/wcag-contrast/issues - npm.io page: https://npm.io/package/wcag-contrast ## Dependencies (1) - [relative-luminance](https://npm.io/package/relative-luminance.md) ^2.0.0 ## Alternatives - [postcss-color-hex-alpha](https://npm.io/package/postcss-color-hex-alpha.md) — 6.4M weekly downloads - [randomcolor](https://npm.io/package/randomcolor.md) — 348.0K weekly downloads - [bows](https://npm.io/package/bows.md) — 1.3K weekly downloads - [ep_prefer_color_scheme](https://npm.io/package/ep_prefer_color_scheme.md) — 260 weekly downloads - [coc-yank](https://npm.io/package/coc-yank.md) — 61 weekly downloads ## Recent versions - 3.0.0 (latest) — 2019-11-05 - 2.1.2-0 (prerelease) — 2018-09-24 - 2.1.1 — 2018-09-24 - 2.1.0 — 2018-08-20 - 2.0.0 — 2018-08-20 - 1.2.0 — 2018-04-16 - 1.1.0 — 2018-03-21 - 1.0.0 — 2018-03-21 - 0.1.2-0 — 2018-03-21 - 0.1.1 — 2018-01-10 - 0.1.0 — 2015-09-18 - 0.0.0 — 2013-09-24 ## README ## wcag color contrast [![CircleCI](https://circleci.com/gh/tmcw/wcag-contrast.svg?style=svg)](https://circleci.com/gh/tmcw/wcag-contrast) This module produces [WCAG](http://www.w3.org/WAI/intro/wcag.php) [contrast ratio](http://www.w3.org/TR/WCAG20/#contrast-ratiodef) measurement and scoring. It's an accessibility standard, intended to make sure websites have high enough contrast to be readable by everyone, including people with [low vision](https://www.aao.org/eye-health/diseases/low-vision) and age-related vision problems. This module is a low-level utility, useful for its implementation of the underlying math: to test a page, you'll want to use something like Google Chrome’s [Lighthouse tools](https://developers.google.com/web/tools/lighthouse/), or the [axe extension](https://www.deque.com/axe/) for Chrome and Firefox. I (personally, speaking as Tom) have doubts about the [universality, accuracy, and application of this particular standard](https://macwright.org/2019/03/30/color-contrast-is-a-problem.html). High contrast is a good value, but I argue that the standard is over-strict and doesn't precisely match human perception. ## API ### luminance Get the contrast ratio between two relative luminance values **Parameters** - `a` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** luminance value - `b` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** luminance value **Examples** ```javascript luminance(1, 1); // = 1 ``` Returns **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** contrast ratio ### rgb Get a score for the contrast between two colors as rgb triplets **Parameters** - `a` **[array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)** - `b` **[array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)** **Examples** ```javascript rgb([0, 0, 0], [255, 255, 255]); // = 21 ``` Returns **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** contrast ratio ### hex Get a score for the contrast between two colors as hex strings **Parameters** - `a` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** hex value - `b` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** hex value **Examples** ```javascript hex('#000', '#fff'); // = 21 ``` Returns **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** contrast ratio ### score Get a textual score from a numeric contrast value **Parameters** - `contrast` **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** **Examples** ```javascript score(10); // = 'AAA' ``` Returns **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** score --- _Source: https://npm.io/package/wcag-contrast · Machine-readable twin of the npm.io package page. 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