Privacy

We do not ask you for anything. Measurements you type, the screen calibration you save and the PDF you build never leave your device — the maths and the PDF are done in your browser, and nothing is sent to a server.

Screen calibration is kept in your browser’s local storage on your own device so you do not have to do it twice. Clearing your browser data removes it. Nothing in it identifies you.

This site uses Google Analytics 4 to count visits and see which pages are read. Analytics sets its own cookies and records a shortened IP address; it never sees what you measured. Google’s own privacy notice explains what it collects at policies.google.com/privacy.

If advertising is switched on later, Google and its partners may use cookies to show ads. You can turn personalised advertising off at any time at adssettings.google.com. This paragraph will say so plainly on the day any ad actually runs.

Questions about any of this: [email protected].