AUDIT CHESSEnter your next opponent's Lichess or Chess.com username. Audit Chess reads their public games and builds a bot that answers with the moves they actually play, as often as they play them. When the game leaves their book, the bot keeps going at roughly their rating.
Their real repertoire
Every book move comes from their own games, picked at the same frequency they choose it.
Transposition-aware
Reach their position by a different move order and the bot still knows their reply.
Their strength after book
Out of book the engine plays human-like moves scaled to their rating, slips included.
Private and free
Games are fetched and played in your browser. No account, nothing uploaded.
It downloads their recent public games, records every move they made in the first 15 moves with the colour you chose, and plays those moves at the same rate they did.
Stockfish takes over, but it picks moves the way a player of their rating would — usually a good move, sometimes a slip. It approximates their strength; it does not copy their personal mistakes.
Yes. It is free, needs no account, and runs entirely in your browser.