Privacy Policy

Last updated: 2026. This is a small hobby project, not a company. We try to collect as little as possible and never sell your data.

What we store

• Your account — your email address and a salted hash of your password (we never store the password itself), or, if you use Google sign-in, your Google account id and email.
• Linked chess accounts — the Chess.com / Lichess usernames you choose to link, and which time controls you want analysed.
• Chess data — games we fetch on your behalf from the public Chess.com and Lichess APIs, the puzzles we generate from your mistakes, and your solve/attempt history.

How we use it

Only to run the service for you: to fetch and analyse your games, build and show your puzzles, track which you've solved, and keep you signed in. We do not use your data for advertising and we do not sell or share it with third parties.

Third parties

We fetch game data from Chess.com and Lichess using their public APIs, and (if you choose it) authenticate you via Google sign-in. Your use of those services is governed by their own policies.

Cookies

We set a single, strictly necessary cookie to keep you signed in. We do not use tracking or advertising cookies.

Deleting your data

You can permanently delete your account and all associated data at any time from your Profile page. Deletion is immediate and irreversible.

Contact

Questions about your data? Email your-contact@example.com.