About elo9000
elo9000 is a chess opening trainer with one job: fix the openings that actually lose you games.
It syncs your real games from Lichess (and chess.com, once linked), walks each one against the repertoire you've built, and finds the exact move where the game left your prep. Every gap becomes something you can fix on the board — with the moves players at your level actually play — and then drill with spaced repetition until it sticks. The analytics page tells you whether it's working.
Sign in with your Lichess account — that's the whole login, no email or password, and it works the same if chess.com is where you actually play. Once signed in, your repertoires and practice sync across your devices: build on the laptop, drill on the phone. See the privacy note for exactly what we store (short version: your prep and your public username — nothing else).
Standing on shoulders
- The Lichess API — game export, opening explorer, cloud eval, rating history.
- The chess.com public API — monthly game archives.
- chessground (the board), chessops (the rules), Stockfish (the engine, running in your browser), and ts-fsrs (the scheduler).
elo9000 is not affiliated with Lichess or chess.com.