Stop making the same mistakes.
DejaChess turns the blunders from your own games into puzzles. Drill the exact positions you misplayed — and watch your most common mistakes disappear over time.
Free while in beta. Analysis runs on your device — we never see your games until you save them.
Import your real games
Link your Chess.com or Lichess username and pull in your recent games. No passwords, no OAuth hoops — both APIs are public.
Stockfish finds your mistakes
Analysis runs in your browser with Stockfish 18 WASM. Every eval swing is detected, classified, and explained in plain language.
Drill your own blunders
Each mistake becomes a puzzle: the position right before you went wrong. Find the move you should have played.
Watch the trend bend
See your most repeated mistake types and whether they're actually declining: “you hang pieces 40% less than 50 games ago.”
How it works
- 1. Enter your Chess.com or Lichess username.
- 2. DejaChess imports your recent games and analyzes them with Stockfish, right in your browser.
- 3. Your blunders, missed tactics, and hung pieces become puzzles.
- 4. Drill them on a spaced-repetition schedule until the right move is reflex.