The service
Chess Blundr is a free website that analyzes chess games, explains mistakes, builds practice puzzles from them and teaches the rules of chess. The service is provided free of charge, and we may change, pause or discontinue any part of it at any time.
Using the site
You may use Chess Blundr for your own personal, non-commercial chess improvement. You agree not to:
- use the site to break any law or to infringe anyone else’s rights;
- use the site to get outside assistance during a game in progress, or otherwise to cheat on Chess.com, Lichess or any other platform or event;
- attempt to disrupt, overload or gain unauthorized access to the site or its hosting;
- use automated tools to make excessive requests to the site or, through it, to the Chess.com or Lichess APIs.
Your games and data
The games you load remain yours. They are processed in your browser and are not uploaded to us. Your practice deck, stats and settings are stored only on your device, so you are responsible for keeping them. Clearing your browser data will delete them, and we cannot recover them. See the privacy policy for details.
Third-party services
Importing games by username uses the public APIs of Chess.com and Lichess. Your use of those services is governed by their own terms. Chess Blundr is not affiliated with, endorsed by or sponsored by Chess.com or Lichess, and we are not responsible for their availability or content.
Accuracy of analysis
Analysis is produced by the Stockfish chess engine running at limited depth on your device, and the move grades and explanations are generated from its output. They are usually helpful but can be wrong, and results may vary between devices. Treat them as a study aid, not as an authority.
Intellectual property and open source
The Chess Blundr name, logo, design and written content belong to us. Parts of the site are built on open-source software and assets that remain under their own licenses, including:
- Stockfish.js, licensed under the GNU GPLv3;
- chess piece artwork by Colin M.L. Burnett, licensed under CC BY-SA 3.0;
- chess.js and cm-chessboard, under their respective open-source licenses.
Nothing in these terms limits the rights those licenses give you.
No warranty
The site is provided “as is” and “as available”, without warranties of any kind, express or implied, including fitness for a particular purpose, accuracy and uninterrupted availability.
Limitation of liability
To the fullest extent permitted by law, Chess Blundr and the people who run it are not liable for any indirect, incidental or consequential damages, or for any loss of data, rating points or games, arising from your use of the site. Because the service is free, our total liability for any claim is limited to zero, or to the lowest amount the law allows.
Changes to these terms
We may update these terms from time to time. When we do, we will change the date at the top of this page. Continuing to use the site after a change means you accept the updated terms.
Contact
Questions about these terms? Email hello@chessblundr.com.