Fitts' Law Overlay

Overlay for Fitts' law measurement and UX tinkering.

A Chrome extension that overlays visual tools for exploring Fitts' law — the relationship between target size, distance, and interaction time in user interfaces.

Free. No account. No analytics.

Not yet published on the Chrome Web Store.

How to use it

Built for UX designers, researchers, and anyone curious about interaction design fundamentals.

Send feedback or report a bug

Privacy policy

Last updated: 8 September 2026

Fitts' Law Overlay is a browser extension that displays an overlay for measuring and exploring Fitts' law. This policy explains what the extension does with your data.

What we collect

We do not collect, store, or transmit your personal data to any server operated by the extension developer. The extension runs locally in your browser. There is no developer-operated backend, analytics, advertising, or tracking. No sale of personal data.

What happens in your browser

Permissions

Typical permissions declared in the Chrome Web Store listing include access to inject the overlay into web pages. The extension does not access data outside the active tab.

Third parties

None. The developer does not send data to third parties. Chrome itself may apply its own policies to extension installation and updates from the Chrome Web Store.

Data retention

There is no developer-held copy of your browsing. Uninstalling the extension removes it from Chrome.

Children

This extension is not directed at children under 13.

Changes

We may update this policy. The "Last updated" date above will change when we do.

Contact

Questions: Feedback