Privacy Policy

Last updated: July 14, 2026

This policy explains what Chess Lab (“we”, “us”) collects, why, and the choices you have. Questions? Reach us via Support.

What we collect

• Account information — the email address and password you sign up with. Passwords are stored hashed by our authentication provider; we never see them.
• Your games — chess games you import from Chess.com or Lichess (move lists / PGN), plus any notes or progress you create while training.
• Analysis data — engine evaluations and move classifications we generate and cache for your games so reviews load quickly.
• Training & in-app progress — which courses, tactics, and endgames you’ve practiced, spaced-repetition schedules, and the in-app currency you earn.
• Billing data — if you subscribe to Pro, our payment processor (Stripe) handles your card. We store only a customer/subscription reference and status — never your full card number.

How we use it

• To provide the service — review your games, run the trainers, track your progress.
• To operate your account and authenticate you.
• To process subscription payments and manage your plan.
• To diagnose problems and improve the product.

We do not sell your personal data, and we don’t use it for third-party advertising.

Who we share it with

We rely on a small set of service providers who process data on our behalf:

• Supabase — authentication and database hosting (your account, games, and progress).
• Stripe — subscription billing and payment processing.
• Our analysis services — the Stockfish engine (hosted on our behalf) and public endgame tablebase services that evaluate positions. Game moves are sent to these for analysis; they receive only board positions, not information that identifies you.
• Email — our email provider sends account and support emails (for example, sign-in confirmations). It receives your email address for that purpose only.
• Hosting — our application and engine are hosted by infrastructure providers who process data solely to run the service.

These providers act as our processors under contract and may store data in the United States or other countries. We do not sell your personal data.

Retention & deletion

We keep your data while your account is active. You can delete your account at any time from your Account page — this permanently removes your account and the data tied to it (games, analysis, progress, and earned currency). Some records may persist briefly in backups before being overwritten, and billing records may be retained as required by law.

Your rights

Depending on where you live (including under GDPR and CCPA), you may have the right to access, correct, export, or delete your personal data, and to object to certain processing. You can exercise deletion yourself from the Account page, or contact us via Support for any other request. We don’t sell personal information.

Automated analysis

Chess Lab evaluates your games and generates lessons automatically (using the Stockfish engine and a rule-based explanation system) so it can teach at scale. This processing only produces study feedback about your chess — it is not used to make decisions that have legal or similarly significant effects on you.

Children

Chess Lab is not directed to children under 13, and we do not knowingly collect personal information from them. If you believe a child under 13 has provided us data, contact us via Support and we will delete it.

Cookies

We use cookies only for essential purposes — keeping you signed in. We don’t use advertising or cross-site tracking cookies.

Changes

We may update this policy as the product evolves. Material changes will be reflected by the “Last updated” date above.