Coloried

Contrast Checker

Use this tool to check the contrast ratio between foreground and background colors. Ensure your text is readable and accessible by following WCAG guidelines.

Text

Color Picker

#000000
Background

Color Picker

#FFFFFF
21.00:1
Contrast Ratio
AAAPass≥ 7.0
AAPass≥ 4.5
APass≥ 3.0
FPass< 3.0

Sample Text

This is how your text will look with these colors.

Button Example

Contrast Examples

Perfect Contrast21:1
Excellent (AAA)12.6:1
Good (AA)5.9:1
Acceptable (A)4.2:1
Poor (Fail)2.1:1

About Contrast Checking

Essential for accessible websites:

  • Ensures readability for all users
  • Meets WCAG guidelines
  • Works across devices and lighting
WCAG CompliantAccessibility FocusedReal-time Testing

WCAG Guidelines

Contrast ratios range from 1:1 to 21:1. Higher is better.

AAA Level (7:1 ratio)

Enhanced contrast for improved readability, especially for people with low vision

AA Level (4.5:1 ratio)

Standard level for normal text, required for most accessibility compliance

A Level (3:1 ratio)

Minimum level for large text (18pt+) and graphic elements

Fail (Below 3:1)

Does not meet accessibility standards, avoid using for text content

WCAG Compliance Levels

AAA≥7:1

Enhanced - Best for low vision users

AA≥4.5:1

Standard - Required for compliance

A≥3:1

Minimum - Large text only

Accessibility Compliance Standards

Luminance Calculation

Step 1: Convert RGB to Linear
if (c ≤ 0.03928)
  c = c / 12.92
else
  c = ((c + 0.055) / 1.055)²⁴
Step 2: Calculate Luminance
L = 0.2126×R + 0.7152×G + 0.0722×B
Step 3: Contrast Ratio
CR = (L₁ + 0.05) / (L₂ + 0.05)
Mathematical Formula Behind Contrast

How It Works

Uses luminance-based calculation for accurate measurement.

Luminance Measurement

Based on human eye perception

Scale Range

1:1 (no contrast) to 21:1 (maximum)

Why It Matters:

Ensures readability across devices and lighting conditions.

Text Size Requirements

Larger text needs less contrast.

Normal Text

4.5:1 for AA, 7:1 for AAA

Large Text (18pt+)

3:1 for AA, 4.5:1 for AAA

Pro Tip:

Aim higher for better accessibility.

Text Size Examples

12px - Small Text
Needs 4.5:1 contrast ratio
Current: 12.6:1 ✓
16px - Normal Text
Needs 4.5:1 contrast ratio
Current: 5.9:1 ✓
18px - Large Text
Needs 3:1 contrast ratio
Current: 5.2:1 ✓
24px - Extra Large
Needs 3:1 contrast ratio
Current: 4.2:1 ✓
Size-Based Contrast Requirements
Test with Real Users
Get feedback from people with visual impairments
Check Different Screens
Test on various devices and brightness levels
Consider Context
Account for surrounding colors and patterns
Use Tools Regularly
Make contrast checking part of your workflow

Best Practices

Start with High Contrast

Begin strong, adjust as needed

Test Early

Check during design phase

Think Beyond Compliance

Aim higher than minimum requirements

Common Mistakes

Gray Text on White

Often fails requirements

Similar Colors

Poor contrast despite looking different

Common Mistakes

Light gray text2.8:1 ✗
Similar blue tones1.8:1 ✗
Green on green1.4:1 ✗
Yellow variations1.9:1 ✗
⚠️ Warning Signs:
  • • Squinting to read text
  • • Difficulty in bright light
  • • Text disappears when printed
  • • Hard to read on mobile