Chess Blunder Puzzles from Your Own Games
Turn your own mistakes into training. This free tool takes the blunders and mistakes from your chess.com and lichess games and replays them as puzzles, so you drill the exact positions where you went wrong.
Just enter your chess.com or lichess.org username and it pulls your recent games automatically — no PGN uploads and nothing to install. It runs in your browser with no signup, a personalized complement to lichess puzzles that trains your real weaknesses instead of random tactics.
Because the puzzles come from positions you actually reached, you practise the tactics and patterns that are costing you rating right now — hanging pieces, missed forks and pins, back-rank weaknesses — instead of a generic set that has nothing to do with how you play.
Why train on your own blunders
Puzzles from your games
Every puzzle comes from a position you actually played, so you fix the patterns that are costing you rating right now.
Find the move you missed
Stockfish verifies the solution, so you learn the strongest continuation you overlooked in the real game.
chess.com & lichess games
Enter your chess.com or lichess.org username and your recent rapid, blitz and bullet games load automatically, ready to mine for mistakes.
Choose your severity
Focus on full blunders, or widen the net to include mistakes and dubious moves depending on how hard you want to train.
Learn the pattern, not the move
Each puzzle shows why your move failed and what the engine preferred, so you recognise the same tactical motif next time it appears.
Free, in your browser
No account and no limits — the engine that builds and checks the puzzles runs locally on your device, so your games are never uploaded.
How to train on your own blunders
Enter your username
Type your chess.com or lichess.org username and your recent games load automatically — no PGN files and no account to link.
Pick your severity
Choose whether to drill only full blunders or to include mistakes and dubious moves as well, depending on how hard you want to train.
Solve the position
You get the exact position from your game and have to find the move you missed — Stockfish checks your answer against its best line.
Fix the pattern
See why your original move failed and what you should have played, then move on to the next blunder and build the habit for real games.
Frequently asked questions
Where do the puzzles come from?
They are generated from the blunders and mistakes in your own chess.com and lichess games, so you train on your real weaknesses instead of random positions.
How do I load my games?
Just enter your chess.com or lichess.org username and your recent games load automatically. There is nothing to upload and no account to connect.
Is it free like lichess puzzles?
Yes, it is completely free with no signup and no daily limits. Unlike a generic puzzle set, every puzzle comes from a position you actually played.
How is the solution checked?
Stockfish evaluates each position locally in your browser, so the puzzle solution is the engine-verified best move you missed in the game.
Can I choose how hard the puzzles are?
Yes. You can train on serious blunders only, or widen the selection to include mistakes and smaller inaccuracies for more frequent, easier practice.
Do you upload my games to a server?
No. Your games are fetched from chess.com or lichess and analyzed entirely in your browser with Stockfish, so nothing is stored on our servers.