What we collect
- Learning progress & preferences — XP, streaks, completed lessons, language and reduced-motion settings. These are stored in your browser (localStorage) and, if you sign in, optionally synced to your account.
- Account info — if you sign in with Google via Firebase Authentication, we receive your email address and a user ID. We do not see your Google password.
- Analytics — to understand which lessons are useful, we use Plausible (privacy-friendly, no cookies, no personal data) and, only if you agree, Google Analytics. See the section below.
- No ad trackers. We do not sell your data or use advertising trackers.
How we use it
Only to run the product: save your progress, sync it across your devices, and remember your preferences. That's it.
Analytics & cookies
We measure usage in aggregate so we can improve the lessons — we never try to identify you personally.
- Plausible Analytics runs on every page. It sets no cookies, collects no personal data, and records only anonymous, aggregated figures (page views, country, and events such as “lesson completed”). Because of this it needs no consent.
- Google Analytics uses cookies, so it only loads after you click “Accept” in the cookie banner. If you decline, it never loads on any page. You can change your choice at any time:
Where it lives
Progress is kept in your browser and, for signed-in users, in Google Firebase (Authentication and Firestore). Firebase is governed by Google's security and privacy terms.
Your choices
- Clear local data anytime from your browser settings (this resets local progress).
- Request account deletion by emailing feedback@cryptomath.org.
- Use the site signed-out — progress then stays only on your device.
Children
CryptoMath is an educational resource suitable for general audiences. If you are under the age required for consent in your country, please use it with a parent or teacher.
Contact
Questions about privacy? Email feedback@cryptomath.org. See also our Terms of Use.