Kasuality: APCA Contrast Validator and OKLCH

by Alessandro Di Berardino · kasuality.com · Accessibility

Established publisherManifest V3 Free

View in Chrome Web Store Data as of 15 Oct 2026

The definitive enterprise APCA accessibility tool. Validate perceptual contrast and generate progressive OKLCH color palettes.

Users

−1 in 30 days

Rating

0.0 / 5

unchanged in 30 days

Ratings

0 in 30 days

Store rank

#270K

#225K among extensions

Version

1.2.4

updated 8 Oct 2026

Users

monthly, 5 months

Latest, 15 Oct 2026: 4 usersMove the mouse over the chart for any month

Ratings count

monthly, 5 months

Latest, 15 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About Kasuality: APCA Contrast Validator and OKLCH

Kasuality Contrast Authority is the definitive enterprise-grade accessibility engine for UI designers and frontend developers. What's new in version 1.2.4: - Header design refinement with a timeless product subtitle ("Kasuality Contrast | AUTHORITY"). - 'Powered by Kasuality.com' link with dynamic user locale detection. WHAT'S NEW IN VERSION 1.2.3 - Precision sub-pixel OKLCH color engine upgrade (Ottosson 2020 model). - Added universal CSS Color 4 input parsing supporting HEX, RGB, RGBA, and modern space/slash syntax. - Enabled workspace session persistence via local storage (restores your custom palette and settings automatically). - Optimized window management: focuses existing application window instead of creating duplicate instances. - Enhanced accessibility with ARIA attributes and improved screen reader support. - Streamlined package distribution footprint by over 98% for ultra-fast startup. Stop relying on obsolete WCAG 2.1 contrast ratios & legacy HSL colors. This extension leverages the Advanced Perceptual Contrast Algorithm (APCA) combined with a progressive OKLCH color space to ensure flawless readability & mathematically perfect chromatic transitions. ⚡ CORE ARCHITECTURE: • APCA Validation Engine: Dynamically calculates perceptual contrast (Lc) based on font weight & size, eliminating WCAG 2.1 false positives. • Native OKLCH Space: Work directly with Lightness, Chroma, & Hue for predictable, uniform color scales. • Magic Fix Algorithm: Instantly resolves accessibility failures. With one click, the engine automatically adjusts the L (Lightness) value to reach your target APCA score. • Smart Suggestions: Automatically generates minimal viable changes & alternative 3-color palettes that pass accessibility standards on your current background. • Enterprise Export: One-click copy for progressive OKLCH, HEX, & RGB CSS variables, ready for production or direct Figma sync. Upgrade your workflow & build digital products that are truly accessible by mathematical design.