sherotree / uwarp-contrast

v0.1.0 2026-11-09 12:52 UTC

Requires

• php: ^8.1

Requires (Dev)

• phpunit/phpunit: ^10.5

MIT

• Sherotree

• color
• accessibility
• wcag
• contrast
• a11y
• uwarp

Published on Packagist.org on 2026-11-09 14:37 UTC

README

WCAG 2.x relative luminance contrast ratios and AA/AAA pass/fail for foreground/background color pairs.

PHP Composer package — API-aligned with the npm package uwarp-contrast.

Live tool: Uwarp Colour Contrast Checker

Install

composer require sherotree/uwarp-contrast

API

Import the functional API (mirrors npm) or use the Contrast / Color classes directly.

<?php

use function Sherotree\Uwarp\Contrast\evaluateContrast;
use function Sherotree\Uwarp\Contrast\getContrastRatio;
use function Sherotree\Uwarp\Contrast\meetsWcag;
use function Sherotree\Uwarp\Contrast\parseHex;
use Sherotree\Uwarp\Contrast\Contrast;
use Sherotree\Uwarp\Contrast\Rgb;

// Hex (#RGB / #RRGGBB, optional #) or Rgb (0–255 per channel)
getContrastRatio('#000000', '#ffffff'); // 21.0

$report = evaluateContrast('767676', '#ffffff');
// $report->ratio, $report->ratioFormatted, $report->wcag (AA/AAA × normal/large)

meetsWcag('#000', '#fff', 'AA', 'normal'); // true

// Class-based equivalent
Contrast::getContrastRatio(new Rgb(0, 0, 0), '#fff');

// WCAG minimum ratios
Contrast::WCAG_THRESHOLDS;

Functions

Function	Description
parseHex(string): Rgb	Parse #RGB / #RRGGBB (optional #)
normalizeColor(string|Rgb): Rgb	Hex string or validated Rgb
relativeLuminance(Rgb): float	WCAG relative luminance (0–1)
contrastRatio(Rgb, Rgb): float	Raw contrast ratio
getContrastRatio(fg, bg): float	Ratio rounded to 2 decimals
evaluateContrast(fg, bg): ContrastResult	Ratio + WCAG pass/fail rows
meetsWcag(fg, bg, level, textSize): bool	Single AA/AAA check

WCAG thresholds: AA normal 4.5, AA large 3, AAA normal 7, AAA large 4.5.

Development

composer install
composer test

Requires PHP 8.1+.

Links

• npm: uwarp-contrast
• Source (npm monorepo): sherotree/uwarp-packages — packages/contrast

License

MIT · Sherotree