Contrast Ratio Calculator
Use the contrast ratio calculator to find out whether the color contrast ratio of your website is accessible or not.
What Contrast Ratio Calculator does
The Contrast Ratio Calculator on Omni Calculator determines the contrast between two colors to verify they meet Web Content Accessibility Guidelines. Users input hex codes for foreground and background colors, and the tool instantly outputs the contrast ratio along with compliance status for WCAG AA and AAA levels across normal and large text sizes. This provides a quick way to assess whether a chosen color pairing will be readable for all users, helping designers avoid combinations that are difficult to discern. The calculator processes the input values and displays the resulting ratios and conformance levels immediately, eliminating the need for manual calculations or guesswork when evaluating color accessibility.
How to use the Omni Calculator Contrast Ratio Calculator
- 1
Open the Contrast Ratio Calculator on Omni Calculator
- 2
Enter the hex code for the foreground (text) color in the R1, G1, B1 fields
- 3
Enter the hex code for the background color in the R2, G2, B2 fields
- 4
Select the text type (normal or large) to view WCAG AA and AAA compliance status
- 5
Review the output contrast ratio and the highlighted lighter/darker color comparison to assess readability
Best for
Web developers, UI/UX designers, and digital accessibility specialists who need to verify that their website color palettes meet WCAG accessibility standards for readable text.
Limitations
- Results depend on accurate hex code input for correct calculations
- Tool focuses on color contrast only and does not evaluate other accessibility factors like font size or layout
- Compliance determinations are based on standard WCAG metrics and may not cover all user needs or specific regulatory requirements
Contrast Ratio Calculator FAQ
- What color contrast ratio is considered accessible according to WCAG?
- A contrast ratio of at least 4.5:1 is required for normal text and 3:1 for large text to meet WCAG AA standards, while a ratio of 7:1 for normal text and 4.5:1 for large text achieves AAA level conformance.
- Can this calculator check contrast for images or logos, not just text?
- The tool is designed for text contrast ratios using foreground and background color inputs; it can be used for any color pairing, but its primary purpose and WCAG compliance levels are calibrated for readable text on websites.
- Does the calculator support color models other than hex codes?
- Yes, the interface includes dropdowns to select sRGB, HSL, HSV, or CMYK models, allowing users to input color values in their preferred format before the tool calculates the ratio.
- What happens if the calculated ratio does not meet WCAG guidelines?
- The tool highlights the contrast ratio result and indicates non-compliance with the selected WCAG level, prompting the user to adjust the foreground or background colors until an accessible ratio is achieved.
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