WCAG Contrast Checker - Color Accessibility Tool with APCA
v1.0.0 Updated Jan 7, 2026 117KiB
Description
π― WCAG Contrast Checker is a color accessibility tool that scans your entire page for contrast issues in one click. Open the Side Panel, and instantly see every text element that fails WCAG compliance β no manual testing required.
Whether you need to verify WCAG 2.1 contrast compliance or test with the modern APCA algorithm, this contrast checker has you covered. The aa contrast checker and aaa contrast checker results appear immediately for all text on the page.
β¨ Key Features
1οΈβ£ One-Click Page Scan
Click the extension icon to open the Side Panel. The accessibility scanner automatically detects all visible text elements, extracts their colors, and calculates contrast ratios. No need to test elements one by one β see the full picture instantly.
2οΈβ£ Smart Grouping
Elements with identical text color and background color are grouped together, reducing visual clutter. Each group shows a sample text preview, the color combination, and CSS selector for quick identification.
3οΈβ£ WCAG Compliance Testing
Get instant results for both AA and AAA accessibility levels:
β’ Normal text (4.5:1 for AA, 7:1 for AAA)
β’ Large text (3:1 for AA, 4.5:1 for AAA)
β’ Filter by pass/fail status to focus on issues
4οΈβ£ APCA Algorithm Support
This APCA contrast checker supports the new perceptual contrast algorithm used in WCAG 3.0 draft. Test your accessible colors with both traditional contrast ratio and modern APCA scoring.
5οΈβ£ Fix Suggestions
Unlike other contrast checkers that only show pass/fail, this color accessibility checker suggests the nearest passing color. Click any failing element to see fix recommendations that preserve your original hue. Apply fixes instantly or copy CSS to clipboard.
6οΈβ£ Element Highlighting
Click any result in the Side Panel to scroll the page and highlight that element with a visual indicator. Easily locate the exact elements that need attention.
π How It Works
β€ Click the extension icon to open Side Panel
β€ Page is automatically scanned for all text elements
β€ View grouped results with contrast ratios
β€ Filter by AA/AAA level, pass/fail status, or text size
β€ Click any result to highlight element on page
β€ See fix suggestions and apply with one click
The web accessibility checker displays an overall accessibility score based on visual weight β larger text and more content carry more weight in the calculation. This helps you prioritize fixes that impact users most.
π Accessibility Score
The contrast ratio calculator provides a weighted score from 0-100 based on:
βΈ Pass/fail status of each text element
βΈ Visual weight (font size Γ text length)
βΈ Total coverage of accessible vs inaccessible text
This score gives you a quick overview of your page's wcag compliance status.
π Who Is This For?
This accessibility contrast checker is designed for:
β’ UX/UI designers checking color accessibility across entire pages
β’ Web developers ensuring ADA compliance before launch
β’ Accessibility specialists conducting audits
β’ QA teams testing WCAG 2.1 contrast requirements
β’ Enterprise teams meeting accessibility standards
Whether you work with design systems, component libraries, or production websites, this wcag contrast checker integrates seamlessly into your workflow.
π‘ Why Choose This Contrast Checker?
Unlike complex accessibility tools like WAVE or axe, this color contrast checker focuses on doing one thing well: finding and fixing contrast issues across your entire page.
What sets us apart:
βΈ Full page scan β not element-by-element testing
βΈ Smart grouping β reduces noise, shows what matters
βΈ APCA algorithm support β ready for WCAG 3.0
βΈ Fix suggestions β not just pass/fail, but actionable fixes
βΈ One-click apply β fix color contrast issues instantly
βΈ Weighted scoring β prioritize by visual impact
π§ Technical Details
The contrast ratio calculator uses the official WCAG 2.1 formula based on relative luminance:
- Luminance calculator computes L values for each color
- Contrast ratio = (L1 + 0.05) / (L2 + 0.05)
- Results range from 1:1 to 21:1
For APCA, we use the SAPC algorithm that provides more accurate perceptual contrast values, especially for dark mode interfaces and colored text.
β Frequently Asked Questions
Q: What is a color contrast checker?
A: A contrast checker is an accessibility tool that measures the difference in luminance between text and background colors. Higher contrast ratio means better readability for users with visual impairments.
Q: What contrast ratio is required for WCAG compliance?
A: For WCAG 2.1 AA level, normal text needs 4.5:1 and large text needs 3:1. AAA level requires 7:1 and 4.5:1 respectively. This WCAG contrast checker tests all these standards automatically.
Q: What is APCA?
A: APCA (Accessible Perceptual Contrast Algorithm) is a new contrast calculation method being developed for WCAG 3.0. It provides more accurate results than the current wcag color contrast formula, especially for dark backgrounds and colored text.
Q: How is this different from other tools?
A: Most tools require manual element selection or show overwhelming full-page reports. This colour contrast checker provides smart grouping, actionable fix suggestions, and one-click fixes β focusing on efficiency.
π± Support
Having issues with the WCAG contrast checker? Found a bug in the color accessibility tool? We would love to hear from you. Use the support tab in Chrome Web Store to reach us.
Start checking color contrast today with this accessibility contrast checker. Scan your entire page, find issues instantly, and fix color contrast problems with one click.
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Permissions (3)
Permissions
activeTabβΉ Can access the current tab when you click the extension scriptingβΉ Can inject scripts into web pages sidePanel
Details
| Version | 1.0.0 |
| Updated | Jan 7, 2026 |
| Size | 117KiB |
| First Seen | Mar 22, 2026 |
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