Instant AA/AAA verdicts
Pick any two colors or sample them from the page and see the WCAG contrast ratio with a pass or fail for each level.
AA / AAA
CK
Developer tools · Accessibility
Contrast Checker grades WCAG contrast on any page, without sending colors anywhere.
Check two colors in the popup or scan a whole page from the side panel and get instant AA/AAA verdicts. Free, local-first and honest about what it can and cannot measure.
Recommended for your browser
Choose where to install
Official stores are the safest choice and provide automatic updates.
CH
Chrome
Detected: Chrome
Other browsers
Developer / manual installation
Use the ZIP only when an official store is unavailable.
- Unzip the file, open the browser's Extensions page, enable Developer mode, then choose Load unpacked.
Manual installations do not update automatically. ZIP files are not one-click installers.
Completely free · no paywall
product screenshot · Contrast Checker popup
product screenshot · Contrast Checker onboarding
product screenshot · Contrast Checker options
product screenshot · Contrast Checker sidepanel
product screenshot · Contrast Checker honest-boundary
Honest boundaries
Gradients and image backgrounds it cannot resolve are marked as unmeasurable instead of being given a made-up ratio.
no fake numbersFree by design
No account, no paywall and no tracking. It exists to make our paid tools easier to trust.
freePrivate by construction
local-first · optional online features disclosed · no data sold
- No analytics
- No telemetry
- No third-party SDKs
- Core processing stays local; optional sync, backup, AI or sharing connects only when you enable it
Questions people ask
Is Contrast Checker free?
Yes. It is a free extension with no account requirement and no paid upgrade.
Do page colors leave my browser?
No. Ratios are computed locally, and the extension only reads a page when you invoke it on that tab (activeTab) — it has no standing access to any site.
What happens when a background can’t be resolved?
You get an explicit "can’t compute" result. Gradients, images and blended layers never produce a fake ratio.
Questions & suggestions
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