Privacy Policy
Last updated: 29 September 2026
Online Ruler is a free on-screen and printable measuring tool. This policy explains what data we handle, how it is used, and the choices available to you. By using this site you agree to the practices described below.
1. Data we store on your device
The on-screen ruler can be calibrated to your display. Calibration values are saved
locally in your browser (via localStorage) and are
never sent to our servers. Clearing your browser data removes them. We do
not require an account to use the tool.
2. Cookies and advertising
This site is supported by third-party advertising provided by Google AdSense. Advertising is switched on only after an AdSense account is connected, so until then no advertising cookies are set. When active, Google and its partners may use cookies (including the DART cookie) to serve ads based on your prior visits to this and other websites. These cookies help show ads that are more relevant to you. Before any advertising is enabled we will implement a consent management platform (CMP), so these cookies stay blocked until you opt in.
- You can opt out of personalized advertising by visiting the Google Ads Settings.
- You can also opt out of third-party vendor cookies for interest-based advertising via YourAdChoices (US) or Your Online Choices (EU).
- Where required by law (for example in the EU/EEA and UK), advertising cookies are loaded only after you have given consent.
3. Analytics
We do not currently use independent third-party analytics trackers. If we add privacy-friendly, aggregated analytics in the future, this section will be updated and any non-essential tracking will follow the same consent requirements as advertising.
4. Information you send us
If you contact us by email, we will use the information you provide only to reply to your message. We do not add it to a marketing list or share it with third parties.
5. Children's privacy
This site is not directed at children, and we do not knowingly collect personal data from children. Because the site is general-purpose and free, advertising shown here is not targeted at children.
6. Data security
Because we store calibration data only on your own device and do not operate user accounts, there is minimal personal data to protect. We follow standard web-security practices for the pages we serve.
7. Changes to this policy
We may update this policy from time to time. The "Last updated" date above reflects the latest revision. Continued use of the site after changes constitutes acceptance.
8. Contact
Questions about this policy can be sent to our contact page.