Convert between HEX, RGB, HSL and test WCAG 2.1 contrast ratios.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. Zero egress.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
RGB [0, 255] ⇄ HSL [0°, 360°, %] ⇄ HEX #RRGGBB ⇄ LAB / LCHHEXRGBHSL“Converting pure cobalt blue across color spaces.”
Parse hex pairs into 8-bit integers.
Calculate cylindrical coordinates.
The color is mathematically normalized across all target web design models.
Use the visual color picker or paste any valid HEX, RGB, or HSL code.
Examine real-time conversion values across all supported color formats.
Click on any color value to copy it directly in standard CSS syntax.
Contrast ratios are calculated using relative luminance: (L1 + 0.05) / (L2 + 0.05), where L1 is the lighter color and L2 is the darker color, according to WCAG 2.1 criteria.
Utilifie is 100% free with zero data tracking. Support continuous development and tool elevations.
Zero-egress companion tools in the Color & Palette suite
Verify text and UI color combinations against WCAG 2.1 Level AA and AAA accessibility standards.
Verify Web Content Accessibility Guidelines (WCAG) AA and AAA compliance ratios
Design multi-stop CSS gradients with angles and live visual preview.
Explore modern OKLCH color space with Lightness, Chroma, and Hue sliders and Hex/RGB/HSL conversion