Live Accessibility Workflow
Compare APCA and WCAG contrast outcomes for the same text/background pair, then pressure-test that pair across real UI scenarios like body copy, buttons, muted labels, and dark surfaces.
Focus
APCA + WCAG
APCA highlights perceptual readability and polarity, while WCAG gives the familiar ratio benchmark teams still rely on today.
Color Roles
Enter two HEX colors and the tool will calculate both WCAG ratio and APCA Lc score in real time. This keeps the first release focused, but already useful for design-system reviews.
Live calculations update as you change either color. APCA scores are shown in Lc, while WCAG keeps the traditional ratio scale.
WCAG Contrast
18.71:1
Strong contrast for body text, dense UI copy, and accessibility-sensitive interfaces.
APCA Contrast
101.4 Lc
Strong APCA contrast for reading-heavy interfaces, settings text, and dense UI content.
Scenario Preview
APCA is especially useful when the same palette needs to survive multiple UI roles. These previews show how one base pair behaves across content, utility text, buttons, and dark surfaces.
APCA 101.4 Lc
Preview Pair
Body copy should stay comfortable through long reading sessions.
This shared preview block is meant for future APCA, WCAG, palette, and design-token workflows.
Foreground
#111827
Background
#F9FAFB
Target strong readability for paragraphs, setting descriptions, and dense interface copy.
APCA 82.1 Lc
Preview Pair
Muted metadata and helper labels still need readable contrast.
This shared preview block is meant for future APCA, WCAG, palette, and design-token workflows.
Foreground
#525762
Background
#F9FAFB
Secondary labels can be softer, but still need enough perceptual separation to remain useful.
APCA -103.3 Lc
Button fills flip the pair direction, which is useful for testing CTA readability and action emphasis.
Foreground
#111827
Background
#F9FAFB
Filled CTA states flip polarity, which often changes APCA outcomes more dramatically than WCAG.
APCA -99.6 Lc
Surface Preview
Dark surface components need stable reading comfort too.
Cards, settings drawers, and dark surfaces benefit from stronger perceptual separation than simple decorative panels.
Foreground
#F9FAFB
Background
#282F3C
Dark surfaces need enough separation for titles, summaries, and utility controls without glowing too hard.
APCA vs WCAG
WCAG uses a familiar contrast ratio, which is still the baseline in many design reviews, documentation flows, and compliance checklists.
APCA accounts for polarity and perceived lightness more directly, which is why it can better reflect the reading comfort of modern UI patterns and dark themes.
Why this matters in real work
This page is not only for comparing two numbers. It helps product teams catch low-contrast body text, avoid weak button states, and review dark-surface readability before design QA, front-end handoff, or accessibility remediation starts costing extra time.
Validate token pairs for body copy, muted labels, CTA buttons, and dark surfaces before they spread across dozens of components.
Give product, design, and engineering one shared contrast reference instead of debating whether the pair only “looks okay” in mocks.
APCA is especially useful when polarity flips. That makes it valuable for themes, overlays, cards, and elevated surfaces where ratio-only review can miss nuance.
Recommended workflow
Next step
Read the guide if you need to explain why APCA and WCAG can disagree, when polarity matters most, and how to use both methods in one practical accessibility workflow.