Contrast Grid Checker

Contrast Grid Checker

Generate comprehensive contrast grids showing WCAG compliance for every color combination. Essential accessibility tool for testing entire color palettes, validating design systems, and ensuring inclusive color schemes with visual matrix analysis.

contrast
accessibility
wcag
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Preset Color Palettes
Quick-start with curated color palettes
Input
Enter colors separated by commas. Supports HEX (#RRGGBB) and RGB formats

Examples:

  • HEX: #FF0000, #00FF00, #0000FF
  • RGB: rgb(255,0,0), rgb(0,255,0), rgb(0,0,255)
  • Mixed: #FF0000, rgb(0,255,0), #0000FF
How it works: Generates an N×N grid showing the contrast ratio between every combination of your colors. Each cell shows the WCAG compliance level (AA/AAA) and a letter grade for quick assessment.

Complete Guide: Contrast Grid Checker

Everything you need to know about using this tool effectively

What is Contrast Grid Checker?

The Contrast Grid Checker tests the contrast ratios between multiple foreground and background colors simultaneously. You enter a list of colors, and the tool creates a grid showing the contrast ratio and WCAG AA/AAA pass/fail status for every combination. This is faster than checking pairs one at a time. All processing happens in the browser.

This tool computes the WCAG relative luminance for each color, then calculates the contrast ratio for every foreground-background pair. The results are displayed in a grid where each cell shows the ratio and whether it passes AA (4.5:1 normal, 3:1 large) and AAA (7:1 normal, 4.5:1 large).

Key Features
Tests all combinations of multiple colors
Shows WCAG AA and AAA pass/fail per cell
Displays exact contrast ratio for each pair
Color-coded grid for visual scanning
Interactive color list editor
Copy grid results
Runs in the browser with no uploads
Supports up to 12 colors
Common Use Cases
When and why you might need this tool

Auditing a design system

Check all color combinations in a design system palette at once instead of testing pairs individually.

Building accessible color sets

Find which colors from a palette can safely be used as text on which backgrounds.

Reviewing brand color accessibility

Test all brand color combinations to ensure they meet WCAG requirements.

Creating accessible chart palettes

Verify that colors used in a chart have sufficient contrast against the chart background.

How to Use This Tool
Step-by-step guide to get the best results
1

Add your colors

Enter hex codes for the colors you want to test.

2

Generate the grid

The tool creates a matrix showing contrast ratios for all pairs.

3

Review pass/fail

Check which combinations pass WCAG AA and AAA for normal and large text.

4

Export results

Copy or download the grid results.

Pro Tips
1

Test both directions: foreground-on-background and background-on-foreground.

2

A combination that fails for normal text may pass for large text.

3

The grid makes it easy to spot which color pairs work and which do not.

4

For accessible designs, ensure every text-background combination in your palette passes AA.

Frequently Asked Questions
How many colors can I test?

Up to 12 colors, creating a 12x12 grid of 144 contrast comparisons.

What WCAG levels are tested?

AA (4.5:1 normal, 3:1 large) and AAA (7:1 normal, 4.5:1 large).

Is my data sent to a server?

No. All calculation happens in your browser. Nothing is transmitted.

How is the contrast ratio calculated?

Using the WCAG formula: (L1 + 0.05) / (L2 + 0.05), where L1 and L2 are the relative luminances of the lighter and darker colors.

Can I save the grid?

Yes. Copy the results or take a screenshot for documentation.