Privacy Policy

This Privacy Policy explains how GrandChess ("we", "us", "our") collects, uses, and protects your personal data when you use GrandChess (the "Service"). We act as the data controller for the personal data described below.

1. Account and authentication

When you create a GrandChess account, we collect the information needed to sign you in and secure your account. If you sign in with Google, we receive your name, email address, and profile picture from Google — we never receive or store your Google password. If you register with email and password, we store your email and a securely hashed password.

2. Profile data

We store the profile details you provide, such as your display name, playing strength, goals, preferred board and piece themes, and language. This lets us personalise your experience across the platform.

3. Chess accounts and imported games

• Linked usernames — the Chess.com and/or Lichess usernames you connect so we can import your games.
• Imported games — the games, moves, results, time controls, and PGN data we fetch from those platforms or that you upload directly.

We import this data on your instruction and use it only to power your analysis, reports, and training.

4. Analysis and generated insights

We analyse your games to produce evaluations, move classifications, mistake detection, opening statistics, and written insights. These results are stored on your account so you can revisit your reports and track progress over time.

5. Training data and improvement profile

As you use the training rooms, puzzles, drills, and exams, we record your activity — such as puzzles attempted, accuracy, streaks, ratings, and weak areas. This builds your personal chess improvement profile so the Service can recommend relevant training and measure your progress.

6. Subscriptions and payments

GrandChess offers free and Premium features. Payments for Premium are handled by our reseller and Merchant of Record, Paddle. Paddle processes your card details, billing address, and tax information directly — we never see or store your full payment details. We retain records of your subscription status and transaction history for accounting and support. See Paddle's Privacy Notice.

7. Analytics and technical data

To operate and secure the Service, we collect technical data such as IP address, device and browser type, language preference, and basic usage telemetry (for example which features you use and error diagnostics). We use this to keep the Service running, prevent abuse, and improve the product.

8. Who we share data with

• Chess.com and Lichess — to import games from the accounts you link.
• AI providers — game data needed to generate written insights is processed by AI models via a secured gateway solely to produce your reports.
• Paddle — our Merchant of Record for payments, tax, invoicing, and refunds.
• Hosting and infrastructure providers — for database, storage, and serving the application.
• Authorities — where required by law.

We do not sell your personal data.

9. Data retention

We keep your account, chess, and training data for as long as your account is active so you can access your history. Transaction records are kept as long as required by tax and accounting law (typically up to 7 years). When data is no longer needed, we delete or anonymise it.

10. Your rights and deletion requests

You have the right to:

• Access the personal data we hold about you;
• Correct inaccurate data;
• Delete your account and associated data;
• Restrict or object to certain processing;
• Receive your data in a portable format;
• Withdraw consent where processing is based on consent;
• Lodge a complaint with your local data protection authority.

To exercise any of these rights or request deletion, email info@grandchess.app. We aim to respond within one month.

11. Security

We use appropriate technical and organisational measures — including encryption in transit, access controls, and least-privilege credentials — to protect your data. No system is completely secure, so we encourage you to use a strong, unique password.

12. Cookies

We use cookies and similar technologies that are necessary to operate the Service, such as keeping you signed in and remembering your preferences. We do not use advertising cookies.

13. Contact

Questions about your privacy? Email us at info@grandchess.app.