Privacy policy
The short version: there is no account to create, nothing to log in to, and no form to fill in. We run Google Analytics to see which pages are useful, and that is the only thing on this site that collects anything about you.
Last updated 16 August 2026.
What we collect
Google Analytics 4 is the only analytics or tracking tool on this site. It
records the pages you visit, roughly where in the world you are (city-level at most), your
approximate device and browser, and how you arrived — a search engine, a link, or directly.
It sets first-party cookies in your browser named _ga and _ga_<id>
so that repeat visits are counted as one person rather than several.
Our web host also keeps standard server logs — IP address, timestamp, requested file, browser user-agent — which is what every web server does by default. They are used for security and diagnosing faults, not for profiling.
What we don’t collect
- No accounts, sign-ups, logins, or passwords — there is nothing to register for.
- No contact forms, newsletters, or mailing lists.
- No advertising, ad networks, or advertising cookies.
- No third-party trackers, social media pixels, session recording, or heatmaps.
- We never sell, rent, or share your data, and we don’t use it to build advertising profiles.
The explorers and the Sheet Builder run in your browser
Every calculation on this site happens locally on your own device. The interactive explorers compute in JavaScript in the page; the Sheet Builder assembles your sheet in the browser and prints it through your browser’s own print dialog. There is no server doing the maths, so the dimensions you type are not transmitted to us.
One honest caveat: the Sheet Builder puts your formula selections into the page URL, so you can copy and share a link to a sheet you built. If you load such a link, that URL — including those selections — is part of the normal page view that Analytics records. The selections are formula names, not personal information.
Things stored on your device
One item: your light/dark theme choice, saved in your browser’s local storage so the site doesn’t forget it between visits. It never leaves your device, and clearing your browser storage removes it.
Embedded widgets
The embeddable widgets at /embed/ deliberately load no analytics at all. If a teacher embeds one of our explorers in a class page, their students are not tracked by us.
Students and children
This is a general-audience reference site. We don’t knowingly collect personal information from anyone, children included — there is no mechanism on the site by which you could give us any. If you are a teacher or parent and the analytics above are a concern for your classroom, the embeddable widgets carry no analytics whatsoever and are the safest way to use this material with students.
Opting out
You can block Google Analytics with your browser’s tracking protection, an ad blocker, a “Do Not Track” or global privacy control setting, or Google’s own opt-out browser add-on. Every part of this site — the explorers, the diagrams, the Sheet Builder, the printable PDFs — works normally with analytics blocked. Nothing here is gated on tracking.
Your rights
If you are in the UK, EU, or California, you have the right to ask what data relates to you, and to ask for it to be deleted. Because we never collect anything that identifies you by name, the practical answer is usually that we hold nothing personally identifying. Ask anyway if you’d like — hello@geometryformula.com — and we’ll tell you exactly what there is.
If this changes
If we ever add advertising, we will say so here before it goes live and add proper consent controls for visitors in the EEA, UK, and Switzerland. We will update the date at the top of this page whenever anything changes.
Contact
Questions about any of this: hello@geometryformula.com. See also our license and citation page and how the site is built.