Game analyzer
Paste a game or import it from Lichess or chess.com. Stockfish checks every move, and you see exactly where the game turned.
Coming soon
Understand every chess mistake you make.
Free chess game analysis with plain-language explanations. See where your game turned, why, and what to play next time.
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Built to make you a better player
Mistakes explained in plain words
Not just “−2.3, best move Nf3”. You get the reason: the undefended piece, the fork you missed, the move that would have saved it.
Puzzles from your own games
Your blunders become practice puzzles, so you train on the mistakes you actually make.
Free to use
Engine analysis runs in your browser, so the core analyzer stays free.
How it works
- 1
Bring a game
Paste PGN text, upload a file, or enter your Lichess or chess.com username.
- 2
Get the analysis
Every move is labelled, from brilliant (!!) to blunder (??), with the key turning points marked.
- 3
Learn the lesson
Read why each mistake happened and get three things to practise next.
Frequently asked questions
Is chessbase.si free?
Yes. Game analysis and explanations are free. A paid plan with extra features may come later, but the core analyzer stays free.
Which games can I analyze?
Any game in PGN format, including games from Lichess and chess.com. Direct import by username is part of the first release.
How are the explanations made?
Stockfish, one of the strongest chess engines, finds the best moves. Our explanation engine then detects what went wrong, such as a hanging piece or a missed fork, and describes it in plain language.
When does the analyzer launch?
We are building it now. The first version includes the game analyzer with move-by-move explanations.