Privacy Policy
Last Updated: March 14, 2026
This Privacy Policy explains what data Online Ruler uses, where it is stored, and what you can control. The ruler runs in your browser and is designed to work without sending your measurements to our servers.
Information We Collect
Online Ruler does not require an account. The core ruler runs locally and does not ask you to upload images or measurement files. For convenience, your browser stores ruler settings on your device, including PPI, unit, display mode, snap preference, and calibration details (time, method, reference label/length). Calibration data may also include a simple device signature (devicePixelRatio and screen width/height) to detect when calibration might be stale.
How We Use Your Information
Local settings are used to remember your preferences between visits and to help show when a saved calibration may no longer match your current display environment. Measurements are calculated in your browser from your current settings.
Information Sharing
We do not sell or share measurement data because Online Ruler does not transmit your measurements as part of its core functionality. Like most websites, the hosting provider may process standard server logs (such as IP address and user agent) for security and reliability.
Data Security
Local settings are protected by your browser and device. You should treat your device as the security boundary: if someone has access to your browser profile, they may be able to see or clear locally stored settings.
Your Rights
You control locally stored settings. You can clear them by removing this site's data in your browser settings. Using private/incognito mode may prevent settings from being saved.
Contact Us
If you have any questions about this Privacy Policy, please contact us.