Color Contrast Checker

Instantly check and improve your color combinations for accessible web and UI design. Enter your foreground and background colors to get the contrast ratio and see if it passes WCAG AA/AAA accessibility standards. Essential for designers, developers, and anyone committed to inclusive digital experiences.

  • Get instant pass/fail for normal and large text
  • Supports HEX and RGB formats
  • Actionable tips for fixing low-contrast issues
  • Learn about WCAG AA/AAA color requirements
A designer examines color combinations for accessibility on a modern computer screen

Online Contrast Checker Tool

Sample Text: Accessible Design Matters
Contrast Ratio: --
Normal Text: --
Large Text: --
Normal text = 14px/18.5px bold. Large text = 18px/24px bold or larger. (What is AA/AAA?)

Understanding WCAG Color Contrast: AA vs AAA

WCAG 2.1 (Web Content Accessibility Guidelines) set the international standard for accessible digital content. For text to be readable by people with visual impairments—including users with low vision or color blindness—sufficient contrast between text and background is essential.

  • AA (Good Accessibility): Minimum 4.5:1 for normal text, 3:1 for large/bold text.
  • AAA (Excellent Accessibility): Minimum 7:1 for normal text, 4.5:1 for large/bold text.
  • Normal Text: 14px (18.5px bold) or less.
  • Large Text: 18px (24px bold) or more.

Meeting AA is required for most legal compliance (including ADA, Section 508, EN 301 549). AAA is recommended for maximum inclusivity but is not mandatory in most cases.

Why Accessibility Matters
Over 1 billion people worldwide live with some form of visual impairment. Accessible design isn't just ethical—it's often required by law, and it improves usability for everyone.

Best Practices for Accessible Color Contrast in Web Design

  • Avoid using light gray text on white backgrounds—it often fails all standards.
  • Use your brand colors, but test them for accessibility before finalizing your palette.
  • For overlays or text on images, always add a semi-transparent background or shadow to increase contrast.
  • Gradients and background images can reduce contrast—test the actual area where text appears, not just the color codes.
  • Be cautious with color-coding: never rely solely on color to convey important information (use icons, underlines, or bold as well).
  • Contrast rules apply to buttons, links, form fields, and icons—not just paragraph text.
Pro Tip
Use a palette generator to create a range of accessible color combinations for your brand or project. Test all major combinations before launch.
Do This
  • Test all text/background pairs
  • Check links and buttons too
  • Adjust colors until you see "Pass"
Avoid
  • Low-contrast text for aesthetic reasons
  • Ignoring contrast on hover/focus states

How to Use the Online Contrast Checker

  1. Enter Colors: Pick colors using the visual picker or enter hex/RGB codes for both text and background.
  2. View Results: Instantly see the contrast ratio and whether your combination passes AA and AAA for both normal and large text.
  3. Interpret Pass/Fail: Green = Pass, Red = Fail. Hover for more info.
  4. Swap or Adjust: Use the "Swap Colors" button to quickly reverse foreground and background, or tweak colors until you meet your desired standard.
  5. Apply Changes: Once you achieve "Pass" for your needed level, use those color codes in your CSS or design system.
Tip: Not sure which color format to use? Both #hex and rgb() are supported. Example: #1C2241 or rgb(28,34,65).

Accessible Color Combinations: Example Table

Foreground Background Contrast Ratio AA (Normal) AA (Large) AAA (Normal)
#234080 #ffffff 11.8:1 Pass Pass Pass
#f6f8fa #234080 14.5:1 Pass Pass Pass
#bbbbbb #ffffff 2.7:1 Fail AA Large Fail
#17A2B8 #ffffff 3.1:1 Fail Pass Fail
#000000 #ffffff 21:1 Pass Pass Pass
#ff0000 #ffffff 4:1 Fail Pass Fail
"Pass" badges indicate compliance for that level. Use these combos for web text, buttons, or UI elements. For more, try the accessible palette generator.

More Color Accessibility Tools

Color Picker

Find, convert, and copy HEX/RGB colors for your designs.
Palette Generator

Create accessible palettes that work together and pass contrast tests.
Color Blindness Simulator

Preview your palette for various types of color vision deficiency.
Gradient Maker

Design gradients and test contrast with overlaying text.

Frequently Asked Questions: Color Contrast & Accessibility

Color contrast is key to making digital content readable for everyone, including users with visual impairments such as low vision or color blindness. Without sufficient contrast, text and interface elements can become difficult—or impossible—to read, excluding millions of users. Good contrast improves usability for all users, not just those with disabilities, and it is a legal requirement in many regions.

AA is the standard level of accessibility required by most laws and organizations. It requires a 4.5:1 contrast ratio for normal text and 3:1 for large text. AAA is a stricter, enhanced level of accessibility that requires 7:1 for normal text and 4.5:1 for large text. AAA is not always achievable for all designs, but aiming for it ensures the most inclusive experience.

The contrast ratio is calculated based on the luminance of the foreground and background colors, using a formula specified by WCAG. It ranges from 1:1 (no contrast, e.g., white on white) to 21:1 (maximum contrast, e.g., black on white). Our tool automatically applies this formula to any hex or RGB color you enter.

Yes, but you may need to adjust shades or pairings to achieve sufficient contrast. Use this checker to test different combinations, and consider using accent colors for highlights rather than for primary text on white. Many brands maintain accessibility by offering both a brand palette and an "accessible palette" for digital interfaces.

If your combination fails, adjust either the text or background color to increase the contrast ratio. Darken the foreground, lighten the background, or vice versa. Use our palette generator to explore new combinations, and always test interactive states (hover, focus) too. Never rely only on color to convey meaning—add icons, underlines, or bold as needed.

Accessible Design: One Click to Inclusion

Our online color contrast checker makes it easy to build accessible, inclusive, and compliant websites. Use it for every project—whether you’re a designer, developer, educator, or business owner. Explore our related tools above to streamline your workflow and make accessibility effortless.