Privacy Policy

Last updated: March 18, 2026

Virtual Ruler ("we", "our", or "the app") is a free browser-based measurement tool available at virtualruler.app. This page explains what information the app stores and how it is used.

1. Information We Collect

We do not collect, transmit, or store any personal information on our servers. The app runs entirely in your browser.

The only data stored is a calibration profile saved locally on your device using your browser's localStorage. This includes:

A calculated pixels-per-millimetre value for your screen
The calibration method used (e.g. credit card, manual, or auto-estimate)
A timestamp of when calibration was performed
A screen fingerprint (screen resolution and device pixel ratio) used to detect when your display settings change

This data never leaves your device and is only used to restore your ruler settings on your next visit.

2. Cookies

Virtual Ruler does not use cookies.

3. Analytics

We may use anonymised analytics services (such as Google Analytics or Netlify Analytics) to understand how many people visit the site and which browsers/devices are used. This data contains no personally identifiable information.

4. Advertising

We may display advertisements served by third-party networks such as Google AdSense. These services may use cookies or device identifiers to show relevant ads. Please refer to Google's Privacy Policy for details on how ad data is handled.

5. Third-Party Services

The app is hosted on Netlify. Netlify may log standard web server data (IP address, browser type, pages visited) as part of normal hosting operations. We do not control or access these logs.

6. Children's Privacy

Virtual Ruler is not directed at children under 13. We do not knowingly collect any information from children.

7. Changes to This Policy

We may update this policy from time to time. The "Last updated" date at the top of this page will reflect any changes. Continued use of the app after changes constitutes acceptance of the updated policy.

8. Contact

If you have any questions about this privacy policy, please open an issue on our GitHub repository.