Colour Contrast Analyser (CCA) is a free desktop tool for macOS and Windows that measures the colour contrast ratio between any two colours on screen, helping designers and developers meet WCAG accessibility guidelines.
What is Colour Contrast Analyser?
Colour Contrast Analyser is a free accessibility utility from TPGi that calculates the contrast ratio between a foreground and background colour, then reports whether that pairing passes or fails the Web Content Accessibility Guidelines (WCAG 2.x) at both AA and AAA conformance levels. It works with any colour on screen — you can type in a hex value, paste an RGB triple, or use the built-in eyedropper to sample directly from a live webpage, a Figma canvas, or anywhere else on your display.
I keep it in my dock alongside Figma. Whenever a client sends a brand palette and asks me to "make it accessible," CCA is the first tool I reach for. The contrast ratio appears instantly, and the pass/fail badge removes all ambiguity — no mental maths, no spreadsheet.
What does Colour Contrast Analyser do best?
CCA's strongest suit is its dead-simple eyedropper workflow: click, hover, sample — and the ratio updates in real time before you even release the mouse button. That live feedback loop is something browser-based tools like WebAIM's contrast checker simply cannot replicate, because they can't see colours outside the browser window.
- WCAG AA and AAA verdicts for both normal text (4.5:1 / 7:1) and large text (3:1 / 4.5:1), displayed simultaneously.
- Colour-blindness simulation — CCA can simulate how your chosen pairing looks under eight vision deficiency profiles (deuteranopia, protanopia, tritanopia, and more), which is a genuinely rare feature at this price point.
- Multiple input formats — hex, RGB, HSL, and the eyedropper all coexist without friction.
- Opacity/alpha support — you can specify transparency on either layer and CCA will composite correctly against a configurable background, which matters when you're checking text over a semi-transparent card.
Where it falls short is real-time page scanning — CCA is a manual, point-and-check tool. If you need an automated audit that flags every low-contrast element across a whole site, pair it with something like Axe DevTools or Deque's browser extension. CCA is the scalpel; those are the CT scanner.
Is Colour Contrast Analyser free?
Yes, Colour Contrast Analyser is completely free to download and use, with no feature gating, no account required, and no subscription tier. TPGi publishes it as a public-good accessibility tool and maintains it actively on GitHub. For a tool this polished, the zero-cost price tag is remarkable — most commercial alternatives charge for far less functionality.
Who should use Colour Contrast Analyser?
Any designer, front-end developer, or QA engineer who ships software or websites intended for human beings should have CCA installed. It is indispensable if your work needs to meet Section 508, EN 301 549, or WCAG 2.1/2.2 compliance — common requirements for government, healthcare, education, and enterprise products.
I also recommend it to brand designers who are specifying colour systems upstream of any digital product. Catching a 2.8:1 ratio at the style-guide stage costs nothing; catching it after a developer has shipped it to production costs everyone something. Even if accessibility compliance is not a formal requirement on your project, the discipline of checking contrast sharpens your eye for legibility in general.
Beginners will find the pass/fail badges self-explanatory. Accessibility specialists will appreciate the colour-blindness simulator and the granular opacity compositing. There is genuinely no user who needs this and would be better served by a different tool at this price.
How does Colour Contrast Analyser compare to browser-based alternatives?
Browser tools like WebAIM's Contrast Checker and Adobe's contrast plugin are convenient but confined to what is inside the browser tab. CCA's system-wide eyedropper reaches Sketch, Figma (running natively), Keynote, PDF documents, and even your terminal — anywhere pixels exist on your screen. That universality is the decisive advantage.
Against dedicated design-tool integrations like Stark (Figma/Sketch plugin), CCA wins on portability and cost; Stark wins on workflow integration if you live entirely inside one design tool. Against Chrome DevTools' built-in contrast tooltip, CCA wins on the colour-blindness simulation and the ability to check colours that are not currently rendered in a DOM element. For most practitioners the right answer is CCA plus one browser-based scanner for automated sweeps — they complement rather than duplicate each other.
What are the best Colour Contrast Analyser alternatives?
If CCA does not fit your workflow, the next-best desktop option is Contrast (by Stark for Mac, paid), which lives in the menu bar and adds a colour picker history. For automated page-level auditing, Axe DevTools and Lighthouse (built into Chrome) are the standard. Polypane embeds a contrast checker alongside live multi-viewport previews, which is worth its subscription if you do heavy responsive work. None of them offer CCA's combination of colour-blindness simulation, opacity compositing, and zero cost in a single native app.
