Chess Openings - ChessAtlas

Chess opening repertoire trainer with spaced repetition and game analysis. Build an opening repertoire you actually remember, check your real games against it, and stop losing to lines you thought you knew. ChessAtlas turns your openings into a training routine: learn each line, review it on a spaced repetition schedule, and connect your real games to catch the exact move where you went off-book.

Build your opening repertoire
- Create your own opening lines move by move on a real board
- Paste a PGN and ChessAtlas turns it into a full repertoire tree
- Fork a ready-made course from the curated opening library and make it yours
- Organize your repertoire by opening, by color and by difficulty
- Custom starting positions (FEN) for the lines that do not start from move one

Train with spaced repetition
- Powered by FSRS, the modern spaced repetition algorithm
- Every variation becomes a review card with its own schedule
- Solid lines wait longer, shaky lines come back sooner
- Set your own target retention and session size
- Practice on a real board, with instant feedback on every move

Import your real games
- Pull your games straight from Lichess and Chess.com, automatically
- ChessAtlas checks every game against your repertoire
- See the first move where you left your preparation, game by game
- Full game analysis: move-by-move accuracy and the quality of every move

Find and fix your deviations
- Automatic detection of where you strayed from your opening prep
- Turn every deviation into a drill and replay it until the right move is automatic
- Close the gap between the variation you studied and the move you played

Why a repertoire trainer, not a move list
An opening only works if you remember it under pressure. A static move list does not test you; a spaced repetition trainer does. ChessAtlas is built around memory: every line you study is scheduled, drilled and brought back right before you would forget it.

Who it is for
Club players and improving players, roughly 1000 to 1600, who want an opening repertoire they can trust in a real game — whether you are building your first opening or sharpening variations you already play. Read mode explains the idea behind each move, not just the notation, so you learn the plan and not only the sequence.

Also inside
- A curated library of opening courses you can fork and edit
- Streaks, levels and a leaderboard to keep the daily habit going
- Multiple board themes
- Your progress syncs across mobile and the web app at chessatlas.net

Free to start, with no time limit: build a repertoire of up to 100 lines, link one Lichess or Chess.com account, import your games, find your deviations and train them with spaced repetition — all included, free. Premium is a subscription that lifts the line cap, unlocks every course in the library, allows unlimited linked accounts and adds priority support; its price and billing period are shown by the store before purchase.

Questions or feedback: https://chessatlas.net