Privacy Policy

Last updated: January 2025

Short version: We collect only what we need to make CheckMate work. We don't sell your data. We don't show ads. Your data is stored securely in Firebase. You can delete your data or stop using the platform at any time.

1. Who We Are

CheckMate ("we", "us", "our") is a chess platform operated independently. We can be reached via the Contact page.

2. What Information We Collect

We collect the following information when you use CheckMate:

Account data (if you sign in with Google): Your Google display name, email address, and profile photo URL. This comes directly from Google OAuth and is stored in Firebase.
Game data: Game results, move history, opponent information, and time stamps for games you play online.
Puzzle data: Number of puzzles solved, failed, and your best streak.
Rating: Your chess rating, which changes based on online game results.
Contact messages: If you submit a contact form, we store your name, email, subject, and message.
Usage data: Anonymous connection events (online/offline status during a game session).

We do not collect passwords (Google handles authentication), payment information, location data, or any data from users who play without signing in.

3. How We Use Your Information

To identify you during online multiplayer games
To display your name and rating on the leaderboard
To save your game history and puzzle progress to your profile
To respond to contact form submissions
To show online/offline status to your opponent during a game

We do not sell your data to third parties. We do not use your data for advertising.

4. Firebase & Google Services

CheckMate is built on Google Firebase, which provides authentication and real-time database services. When you sign in with Google, your authentication is handled by Google's OAuth system. Firebase stores your data on Google Cloud infrastructure. Firebase is subject to Google's privacy policies.

The Firebase Realtime Database and Authentication services comply with GDPR and other major data protection regulations.

5. Data Storage & Security

Your data is stored in Firebase Realtime Database, protected by Firebase security rules that ensure:

Only you can write to your own profile data
Only authenticated game participants can write to a game room
Contact messages can only be written, not read publicly

We use HTTPS for all connections. Firebase encrypts data at rest and in transit.

6. Local Storage

CheckMate uses your browser's localStorage to save your settings preferences (board theme, sound settings, etc.). This data never leaves your device and is not sent to our servers. You can clear it anytime in Settings → Privacy → Clear Local Storage.

7. Your Rights

You have the right to:

Access: View your profile data on the Profile page
Correction: Update your display name in Settings
Deletion: Contact us to request deletion of your account and all associated data
Opt-out: Stop using CheckMate at any time — signing out removes your active presence
Portability: You can export your game history via the Games page

8. Children's Privacy

CheckMate is not directed to children under the age of 13. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has provided us with personal information, please contact us.

9. Changes to This Policy

We may update this Privacy Policy from time to time. The "Last updated" date at the top will reflect any changes. Continued use of CheckMate after changes constitutes acceptance of the updated policy.

10. Contact

If you have questions about this Privacy Policy or your data, please contact us.