Terms of Service

1. What BlunderLoop is

BlunderLoop is a free, open-source chess game-review and training tool. You can paste a PGN or import your public games, get a Stockfish-based report of the mistake that mattered, and train that mistake as a drill. The service is currently a free beta: paid plans do not exist, and no feature creates charges, subscriptions, or auto-renewals.

2. Your content and your games

Games you analyze anonymously are processed on your own device and stored in your browser's local storage. You keep all rights to your games and PGN files. If you create an account later, data you choose to save is stored so the service can work for you, and for no other purpose.

3. Acceptable use

• Do not use BlunderLoop, or any engine output it shows, to assist you during a live game. See our Fair Play statement.
• Only import games that are publicly available or that you have the right to analyze.
• Do not attempt to disrupt the service, abuse rate limits, or scrape other users' data.

4. Accounts and age

Creating an account requires meeting the digital-consent age in your region. If you don't meet it, the local analysis tools remain available without an account; we will not collect account data from you.

5. No warranty

BlunderLoop is provided "as is", without warranties of any kind. Engine evaluations are automated estimates and can be wrong. We may change, pause, or discontinue features of the beta at any time.

6. Account deletion and payment records

Requesting account deletion pauses access immediately and schedules permanent cleanup after a seven-day cancellation window. Signing in during that window only lets you review or cancel the request. We request cancellation of automatic renewal when deletion is scheduled; restoring the account does not automatically restart the subscription. A merchant of record may retain the minimum transaction records required by tax, fraud-prevention, refund, or dispute law. BlunderLoop does not present legally required records, offline device copies, or unexpired infrastructure backups as synchronously erased.

7. Open source

BlunderLoop builds on open-source software, including Stockfish (GPL-3.0). Attribution and source pointers are listed on the Licenses page.

8. Changes to these terms

If these terms change in a way that matters, we will post the updated version here with a new date before it takes effect. Continuing to use the service after that date means you accept the updated terms.