Cookies & Browser Storage
This statement explains everything PiGrids Maths stores in your browser when you use PiGrids, why each item is there, and how to control it.
Last updated: August 2026. This document is provided for general information and does not constitute legal advice to you.
What this means
- We set no cookies at all until you sign in.
- Signed in, we set the cookies that keep you signed in - nothing else.
- We remember whether you chose light or dark mode. That's it.
- No advertising, marketing or social-media trackers. None, anywhere.
- You can clear or block all of it - but signing in will stop working.
Document version: 1.0
1. Before you sign in
Browsing our public pages - the home page, pricing, this statement - sets no cookies whatsoever. You can confirm that yourself in your browser's developer tools. Most education sites cannot say this, because most carry advertising or analytics tags. We do not.
2. When you sign in
Signing in sets session cookies from Supabase, our authentication provider. They hold the token that proves the browser is yours, so that every page you open afterwards knows who you are. They are essential: block them and signing in cannot work, because there is nowhere for the proof to live. They are cleared when you log out.
3. Your theme preference
We store one item in your browser's local storage - whether you chose light or dark mode - so the page does not flash the wrong colours on your next visit. It is not a cookie, it is never sent to us, and it contains nothing about you beyond that one choice.
4. Cookies we do not set ourselves
Our site is delivered through Cloudflare, which may set its own short-lived cookie to tell real visitors from automated traffic. That is a security measure, not tracking, and we neither read it nor receive it. If something goes wrong on a page, Sentry records the technical fault so we can fix it; that is described in our Privacy Policy.
5. Advertising and tracking
We do not use advertising trackers, marketing cookies, social-media pixels or cross-site tracking of any kind. We do not sell or share what you do here with advertising networks, and we do not build profiles for advertising.
This is a commitment, not a description of what we happen to do this month. If we ever wanted to measure an advertising campaign, we would have to update this statement and our Privacy Policy and give you a way to refuse it before setting anything - not afterwards.
6. How to control it
Every browser lets you view, block and delete cookies and local storage, usually under Settings → Privacy. Clearing them signs you out and resets your theme choice; blocking them for pigrids.com means you will not be able to sign in at all. Nothing else on the site depends on them.
7. Contact
Questions about anything here - email [email protected].