Want to learn chess openings but do not have a ready-made repertoire? Or do your prepared lines disappear when you need them over the board? Chess Opening Trainer helps you understand opening ideas, build a repertoire, and remember it through focused practice and spaced repetition.

Learn instead of only memorizing:

- Start with two small curated repertoires for White and Black
- Understand why a move works, why it matters now, and what happens if you delay it
- Compare alternatives and see which plans suit different playing styles
- Read teaching notes after answering in the Trainer

Build or import your repertoire:

- Create and edit opening books on an interactive chessboard
- Paste PGN text or choose a `.pgn` file
- For player profiles aged 13 or older, import a public Lichess Study by URL or ID
- Keep PGN variations as branches and comments as teaching notes
- Maintain separate repertoires for White and Black

Practice what needs attention:

- Smart spaced repetition prioritizes weaker and due positions
- Incorrect positions return after two intervening tasks
- Immediate feedback shows the correct move and, when available, the idea behind it
- Focused sessions and statistics make progress visible

For player profiles aged 13 or older, review what happened in real games:

- Import public games by Chess.com or Lichess username
- Explore which continuations appeared from the current board position
- See how often each move occurred in your imported games
- Compare games with the selected opening book and find the first deviation
- Jump to a position, extend your repertoire, or practise the mistake

Chess Opening Trainer is designed for beginner and intermediate hobby players aged 9 and older who want a structured way to learn and practise openings. The interface is available in English and Hungarian, with light and dark themes. You do not need an existing repertoire to begin.

At first use, choose the player's age range. The choice stays on the device. For players under 13, online chess services, feedback email, and rating actions are unavailable; local books, PGN import, training, statistics, and reminders remain available.

No Chess.com or Lichess password is required. For profiles aged 13 or older, public games and public Lichess Studies are loaded through their public services.

Chess.com and Lichess are trademarks of their respective owners. Chess Opening Trainer is not affiliated with or endorsed by Chess.com or Lichess.