Privacy Policy

1. Overview

TrueElo ("the Service") is committed to protecting your privacy. This Privacy Policy explains how we handle information when you use our chess analysis tool at trueelo.app.

Key Point: TrueElo is designed with privacy in mind. The analyzer and drill features require signing in with your Lichess account — we read only your Lichess username and ratings to tune analysis to your level, and never post to your account. Your chess data is stored privately under your account so it follows you between devices, and you can export or delete all of it at any time — section 3.2 below lists exactly what that is.

2. Information Collection

2.1 Lichess Sign-In

The analyzer and drill features require signing in with your Lichess account (OAuth2 PKCE). Through that sign-in, TrueElo reads:

• Lichess username: Shown in the account menu
• Lichess ratings and game counts: Used to tune analysis to your level

The OAuth token is stored in your browser's local storage, not on our servers. TrueElo never posts to your Lichess account, and signing out removes the token. The public statistics pages work without signing in.

2.2 What We Do Not Collect

• Email addresses or passwords (authentication is handled by Lichess)
• Geolocation data
• Device fingerprints
• Cross-site browsing history

Note: If you voluntarily submit the contact form, your name, email, and message are sent to our form processor (Formspree). See Section 4 for details.

3. Data Storage

TrueElo keeps reusable chess statistics and engine results on your device. Your own saved data is kept privately under your account.

3.1 Local Cache

To avoid repeating work, TrueElo caches statistics and engine results in your browser:

• Game statistics: Aggregate win/draw/loss data fetched directly from Lichess, kept on your device against the position it describes
• Engine evaluations: Stay on your device. The engine runs in your browser and its results are cached there, not shared
• No personal data: The statistics cache holds chess positions and aggregate results, separately from your saved account data
• Retention: Lichess statistics expire after six months. Engine results are reused until cleared or the engine version changes

3.2 Your Own Data

Your own data is stored privately under your account, so it is there on every device you sign in to:

• your saved opening lines
• your drill progress
• the board positions captured from your own games
• the opening lines captured from your own mistakes
• your settings
• your drill streak

It is stored with Google Firebase under your Lichess account ID, and a copy is cached on each device you use so the app works offline and stays fast. Only your account can read it. Nobody else's account can, and we do not sell it, share it, or use it to train anything.

You can download all of it at any time with Export in Settings, bring a file back with Import, and delete all of it — from your account and from this device — withDelete everything in Settings.

Delete everything destroys your saved opening lines, the board positions and opening lines captured from your own games, the reports made from reading those games, the chess accounts you have linked, drill progress, settings. Two records stay, because they are ours rather than yours: which free reports you have already used and how many accounts you have ever linked as your own. Keeping them is what stops one press of the button handing out a second helping of what is given away free; neither appears anywhere as your data, and neither says anything about your chess.

4. Third-Party Services

TrueElo uses the following third-party services:

5. Chess Engine Processing

Chess engine analysis runs entirely in your web browser. All position analysis happens locally on your device:

• No chess positions are sent to any server for engine analysis
• No move recommendations are transmitted externally
• Engine processing uses only your device's resources

6. Data Retention

• Local cache: Lichess statistics expire after six months; engine results are reused until cleared or the engine version changes
• Your own data: Kept under your account until you delete it via Settings
• Lichess OAuth token: Stored in your browser; removed when you sign out

You can delete everything at any time with “Delete everything” in Settings, which removes it from your account as well as this device. Clearing your browser's site data on its own only clears this device — signing in again brings your account's copy back.

7. Hosting and Server Logs

TrueElo is a static website with one server-side endpoint, the sign-in one described in section 4. When you visit the site, our hosting provider may generate standard web server logs, which could include:

• IP address
• Browser type and version
• Pages visited and timestamps
• Referring URL

These logs are controlled by the hosting infrastructure, not by TrueElo. We do not access, analyze, or process these logs. Contact the hosting provider for their data practices.

8. Data Security

What is stored, and how it is protected:

• Local cache: Chess positions, aggregate game statistics and engine results stay on your device
• Your own data: Held under your Lichess account ID with Google Firebase, and readable by your account alone — enforced by access rules on the database itself, not only by the app
• Diagnostics: Error and performance reports go to Sentry as described in section 4

We use HTTPS for all connections to encrypt data in transit.

9. Your Rights and Data Portability

Your data is yours, and you can take it or remove it at any time:

• Access: View your data in the app at any time
• Export: Download everything as a single file via Settings → Data Backup
• Portability: Export your repertoire as standard PGN
• Delete: “Delete everything” in Settings removes it from your account and this device

Your Lichess account itself is governed by Lichess — revoking TrueElo's access is available in your Lichess account preferences.

10. Children's Privacy

TrueElo asks for no name, email address, or payment details, from anyone, including children under 13 (COPPA) or under 16 (GDPR). The only identifier we hold is the Lichess account ID of a player who chose to sign in, and what sits under it is their own chess work. The Service is suitable for users of all ages.

11. International Users

TrueElo uses cloud services that may store data across multiple regions globally. See the Firebase Privacy Policy, Lichess Privacy Policy, and Formspree Privacy Policy for their international data handling practices.

12. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be indicated by updating the "Last updated" date at the top of this page. We encourage you to review this policy periodically.

Material changes will be reflected in the date; continued use after changes constitutes acceptance.

13. Contact

For questions about this Privacy Policy, please contact us.