# ChessAtlas > ChessAtlas is a chess opening repertoire trainer. Players build, import, and study chess openings with spaced repetition (FSRS), practice against a trainer that catches deviations in real time, and import their own games from Lichess and Chess.com to find the moves they got wrong. ChessAtlas is designed for club players (1200-2000 Elo) who want to actually remember their opening preparation instead of re-learning the same lines over and over. The app combines three ideas that usually live in separate tools: - A PGN-based repertoire editor with branching variations, comments, and priority tags - Spaced-repetition review of positions (FSRS algorithm) so you only study what you're about to forget - A game importer that diffs your real games against your repertoire and surfaces the exact move where you deviated The marketing site and blog live at https://chessatlas.net. The training app itself lives at https://app.chessatlas.net. ## Core features - [Repertoire builder](https://chessatlas.net/features/repertoire-builder): PGN editor with branching lines, comments, priority tags, and auto-merge of duplicate positions - [Spaced repetition](https://chessatlas.net/features/spaced-repetition): FSRS-based review scheduling so you practice only the positions you're about to forget - [Opening trainer](https://chessatlas.net/features/opening-trainer): practice variations with automatic opponent moves, hint mode, and flashcard-style review - [Deviation finder](https://chessatlas.net/features/deviation-finder): imports your real games and flags the exact move where you left your repertoire - [Game import](https://chessatlas.net/features/game-import): one-click import from Lichess and Chess.com with automatic repertoire diffing - [Memorize openings](https://chessatlas.net/memorize-openings): the method behind the app — how to memorize an opening repertoire and actually retain it ## Comparisons ChessAtlas is not affiliated with, endorsed by, or partnered with any of the products compared below. Each comparison is written by the ChessAtlas team. - [All ChessAtlas comparisons](https://chessatlas.net/vs): hub listing every side-by-side comparison with pricing - [ChessAtlas vs Chessable](https://chessatlas.net/features/vs-chessable) - [ChessAtlas vs Lichess Studies](https://chessatlas.net/features/vs-lichess) - [ChessAtlas vs ChessTempo](https://chessatlas.net/features/vs-chesstempo) - [ChessAtlas vs ChessReps](https://chessatlas.net/features/vs-chessreps) - [ChessAtlas vs Chessbook](https://chessatlas.net/features/vs-chessbook) - [ChessAtlas vs ChessFlare](https://chessatlas.net/features/vs-chessflare) - [ChessAtlas vs Chess Position Trainer](https://chessatlas.net/features/vs-chesspositiontrainer) ## Opening catalogue Every opening page explains the opening, its main variations and traps, then links to a ready-made repertoire to train it. - [All chess openings](https://chessatlas.net/openings): the full catalogue with filters - [Openings for White](https://chessatlas.net/openings/for-white) - [Openings for Black](https://chessatlas.net/openings/for-black) - [Openings for beginners](https://chessatlas.net/openings/for-beginners) - [Aggressive openings](https://chessatlas.net/openings/aggressive) - [Positional openings](https://chessatlas.net/openings/positional) - [French Defense](https://chessatlas.net/openings/french-defense) - [Sicilian Defense](https://chessatlas.net/openings/sicilian-defense) - [Caro-Kann Defense](https://chessatlas.net/openings/caro-kann) - [Scandinavian Defense](https://chessatlas.net/openings/scandinavian-defense) - [Petrov Defense](https://chessatlas.net/openings/petrov-defense) - [Italian Game](https://chessatlas.net/openings/italian-game) - [Ruy Lopez](https://chessatlas.net/openings/ruy-lopez) - [Scotch Game](https://chessatlas.net/openings/scotch-game) - [Fried Liver Attack](https://chessatlas.net/openings/fried-liver-attack) - [Vienna Game](https://chessatlas.net/openings/vienna-game) - [King's Gambit](https://chessatlas.net/openings/kings-gambit) - [Evans Gambit](https://chessatlas.net/openings/evans-gambit) - [Ponziani Opening](https://chessatlas.net/openings/ponziani-opening) - [Bishop's Opening](https://chessatlas.net/openings/bishops-opening) - [Danish Gambit](https://chessatlas.net/openings/danish-gambit) - [Queen's Gambit Accepted](https://chessatlas.net/openings/queens-gambit-accepted) - [Queen's Gambit Declined](https://chessatlas.net/openings/queens-gambit-declined) - [London System](https://chessatlas.net/openings/london-system) - [King's Indian Defense](https://chessatlas.net/openings/kings-indian-defense) - [Nimzo-Indian Defense](https://chessatlas.net/openings/nimzo-indian-defense) - [Englund Gambit](https://chessatlas.net/openings/englund-gambit) ## Opening guides (Blog) - [The French Defense](https://chessatlas.net/blog/opening-theory/the-french-defense-a-solid-and-strategic-choice-against-1e4) - [The Queen's Gambit](https://chessatlas.net/blog/opening-theory/the-queens-gambit-a-complete-guide-to-1d4-d5-2c4) - [The Caro-Kann Defense](https://chessatlas.net/blog/opening-guides/the-caro-kann-defense-a-solid-choice-against-1e4) - [The London System](https://chessatlas.net/blog/opening-guides/the-london-system-the-perfect-low-maintenance-opening-for-busy-players) - [The Sicilian Defense](https://chessatlas.net/blog/opening-guides/the-sicilian-defense-a-complete-guide-for-intermediate-players) - [Italian Game vs Ruy Lopez](https://chessatlas.net/blog/opening-guides/italian-game-vs-ruy-lopez-which-opening-should-you-play) - [5 Best Openings for Club Players](https://chessatlas.net/blog/opening-guides/the-5-best-chess-openings-for-club-players-1200-1800-elo) - [Best Openings for Beginners](https://chessatlas.net/blog/opening-guides/best-chess-openings-for-beginners-5-simple-systems-that-actually-work) ## Repertoire building and study technique - [How to build your first chess opening repertoire](https://chessatlas.net/blog/opening-repertoire-building/how-to-build-your-first-chess-opening-repertoire-a-beginners-guide) - [How deep should you learn your openings?](https://chessatlas.net/blog/opening-repertoire-building/how-deep-should-you-learn-your-openings-a-guide-by-rating-level) - [How to memorize chess openings](https://chessatlas.net/blog/opening-repertoire-building/how-to-memorize-chess-openings-and-actually-remember-them) - [Spaced repetition for chess: why it works](https://chessatlas.net/blog/spaced-repetition-training/spaced-repetition-for-chess-openings-complete-fsrs-guide) - [How to retain chess openings with spaced repetition](https://chessatlas.net/blog/spaced-repetition-training/how-to-retain-chess-openings-with-spaced-repetition) - [How to analyze your games to improve your repertoire](https://chessatlas.net/blog/game-analysis-and-review/how-to-analyze-your-games-to-improve-your-opening-repertoire) ## Product - [Pricing](https://chessatlas.net/pricing) - [Sign up](https://app.chessatlas.net/register) - [Log in](https://app.chessatlas.net/login) - [Public library of prebuilt repertoires](https://app.chessatlas.net/library) ## Optional - [Contact](https://chessatlas.net/contact) - [Privacy policy](https://chessatlas.net/privacy) - [Terms of service](https://chessatlas.net/terms) - 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