Normal text (16px) — The quick brown fox jumps over the lazy dog.
Large text (24px) — Accessibility matters.
Large bold text (18.66px Bold)
What Is the Get-Tools Color Contrast Checker?
The Color Contrast Checker from Get-Tools is a free, browser-based accessibility tool designed to help designers, developers, and content creators evaluate whether their chosen text and background color combinations meet the Web Content Accessibility Guidelines (WCAG) established by the World Wide Web Consortium (W3C). By instantly calculating the contrast ratio between any two colors, the tool provides clear pass or fail verdicts for both AA and AAA compliance levels, covering normal-size and large-size text. Whether you are building a brand-new website, redesigning an existing interface, or simply reviewing a single call-to-action button, this tool gives you the information you need in seconds.
How Does It Work?
Using the tool is straightforward. Pick a foreground (text) color and a background color with the built-in color picker or type a hexadecimal code directly into the input field. The tool immediately computes the relative luminance of each color following the sRGB linearization formula defined in WCAG 2.x, then derives the contrast ratio using the standard equation: (L1 + 0.05) / (L2 + 0.05), where L1 is the luminance of the lighter color and L2 is the luminance of the darker color. The result ranges from 1:1 (no contrast at all) to 21:1 (maximum contrast, such as pure black on pure white).
Four individual WCAG checks are displayed simultaneously: AA for normal text (requires at least 4.5:1), AA for large text (requires at least 3:1), AAA for normal text (requires at least 7:1), and AAA for large text (requires at least 4.5:1). A live preview area renders sample text at different sizes using your chosen colors, so you can see exactly how readable the combination will be in a real-world context. You can also swap the foreground and background colors with a single click or generate a random color pair for inspiration.
Understanding WCAG Contrast Standards
The Web Content Accessibility Guidelines classify contrast requirements into two conformance levels. Level AA is the minimum acceptable standard for most public-facing websites. It mandates a contrast ratio of at least 4.5:1 for normal text (below 18pt, or below 14pt bold) and 3:1 for large text (18pt and above, or 14pt bold and above). Many countries and jurisdictions explicitly require AA conformance under their disability-discrimination or digital-accessibility laws.
Level AAA represents the enhanced standard. It requires a 7:1 ratio for normal text and 4.5:1 for large text. While achieving AAA across an entire site can be challenging, it is strongly recommended for critical content such as healthcare portals, financial dashboards, government services, and educational platforms where readability is paramount.
Why Color Contrast Matters
Approximately 8 percent of men and 0.5 percent of women worldwide experience some form of color vision deficiency. Millions more suffer from age-related vision impairment, cataracts, glaucoma, or macular degeneration. Even users with perfect eyesight struggle to read low-contrast text when using their phones in bright sunlight or on low-resolution displays. Poor contrast leads to higher bounce rates, lower engagement, and frustrated visitors who may never return to your site.
Legal compliance is another compelling reason. The European Accessibility Act (EAA), the Americans with Disabilities Act (ADA), Section 508 in the United States, and the Accessibility for Ontarians with Disabilities Act (AODA) in Canada all reference WCAG as the benchmark for digital accessibility. Non-compliance can result in lawsuits, fines, and significant reputational damage.
Impact on SEO and User Experience
Search engines like Google increasingly factor user-experience signals into their ranking algorithms. Pages with poor contrast tend to have higher bounce rates and shorter dwell times, both of which can negatively affect your search rankings. Google's Core Web Vitals initiative and its broader emphasis on page experience mean that accessibility improvements, including proper color contrast, can provide a measurable SEO advantage. By ensuring your site is easy to read for everyone, you simultaneously satisfy accessibility requirements and boost organic visibility.
Privacy and Security
The Color Contrast Checker runs entirely in your browser. All calculations are performed locally using JavaScript, and no color data is transmitted to any external server. Get-Tools does not collect, store, or share any information about the colors you test. There are no tracking cookies, no analytics tied to your color choices, and no server-side processing. Your design work remains completely private.
Practical Use Cases
This tool serves a wide range of professionals and scenarios. UI/UX designers use it during the wireframing and prototyping phase to validate their color palettes. Front-end developers rely on it when implementing designs to confirm that coded colors match WCAG requirements. Content managers check article text and background combinations before publishing. Accessibility auditors use it as part of comprehensive WCAG audits for corporate, government, and educational websites. Marketing teams verify that email campaigns, banner ads, and social-media graphics maintain sufficient contrast for maximum readability and engagement.