Terms of use
Chess Strategy is free, open-source software (GNU AGPL v3), made by one person in their spare time. By using the site you agree to these terms.
The service
The site is free, with no ads and nothing to sell. Donations through Ko-fi are optional gifts and unlock nothing: everyone gets the same app. It is provided as it is, without any guarantee: it may change, have errors, or be unavailable at times. Training positions and engine evaluations are for learning and may be wrong.
Your account
You log in with Lichess or Google; we never see your password. You can delete your account and everything in it at any time: Profile › Delete my account. What we keep, and why, is explained in the privacy policy.
Fair use
Please use the site for your own training. Don't try to break it, overload the account server, or use it to collect other people's data. Accounts used that way may be removed.
Other sites
Your games come from Lichess and Chess.com, and logins go through Lichess or Google: their own terms apply to your accounts there. This site is not affiliated with Lichess, Chess.com or Google.
The code
The source code is on GitHub under the GNU Affero General Public License v3.0: you may use, study, change and share it under that licence.
Changes and questions
These terms may be updated; the latest version is always on this page. Questions or feedback: open an issue on GitHub.
Last updated: 22 October 2026.