Learn your chess openings,
and actually remember them.
Your repertoire, in random order, against real-game odds. Import the studies you already have — a Lichess export, or any PGN — learn them line by line like a course, then drill them with the variations shuffled, against a sparring partner that answers the way players at your rating actually do. Free, in your browser, nothing to install.
Everything a paid repertoire course does, on your own lines — free
All of it is free. A free account brings your studies in, drills them the way your opponents will actually play them, and scores them against your own games from Lichess and Chess.com — and you can see the whole thing working in the demo account before you make one.
Build a repertoire from what you already have
Paste or upload a PGN — a Lichess study export, or anything else. Arrows, highlights and comments come across with it. Group it into books and chapters, and share a whole book with another player.
Learn a line like a course, then remember it
Move-by-move learning with your study's own commentary beside the board, the way a course teaches — then drill what you learned. Not spaced repetition on flashcards: the variations come up in a different order every time, so what sticks is the position, not the sequence.
Practice against the moves people actually play
Three training modes: cover every branch of your repertoire, drill only the lines you will realistically meet at your rating, or let your sparring partner leave theory and catch it at that. Which reply it picks is weighted by 50 million real games at your level.
See which of your chess openings are winning
Connect Lichess or Chess.com and your games come in every night. Your score in any line you play, the openings that earn points and the ones that leak them, and a check on how far your games really follow your book.