ChessDriller is a free, open-source web application for drilling opening repertoires using spaced repetition. Unlike platforms that lock you into their own repertoire content, ChessDriller lets you import any PGN file — whether built yourself, exported from Lichess studies, or downloaded from another source — and trains you on it.

The trainer presents positions from your repertoire and asks you to find the correct move. A spaced repetition algorithm tracks your accuracy and schedules lines you struggle with more frequently. Progress is stored in your browser locally, so no account is required.

ChessDriller is a good choice for players who have already built or purchased a repertoire and want a lightweight, no-frills way to drill it without paying for another platform. The source code is freely available on GitHub.