Opening repertoire questions:
reasonable doubts.

A solid repertoire starts with a few main lines picked to match your style. On ChessNotes you build a visual tree: each branch is a variation, each node a move. Write a note on any move: the idea, the trap, the plan. If you already play online, start from what you play: ChessNotes can build a first repertoire from your Chess.com and Lichess games. The point isn't covering everything, it's knowing what you actually play cold. Aim for 3-4 openings with white and 2-3 systems with black, then expand only when the basics are solid.

Passive repetition doesn't work. You need active spaced repetition: see the position, find the move, get feedback. ChessNotes uses FSRS-5, a modern open-source spaced repetition algorithm, to show you the right variations at the right time. A short daily session replaces hours of rereading. No paper flashcards, no manual Anki — everything in one flow.

Yes — ChessNotes is free, with no credit card and no cap on variations. Chessable is a good product, but it is built around its course catalogue, and most of its courses are paid (a selection is free). ChessNotes was built for people who want to build and train their own repertoire, not follow someone else's. Import free Lichess studies, analyze with built-in Stockfish 19, and run FSRS-5 drills without a subscription.

Every time you answer a position, the algorithm estimates how hard that move is for you and schedules the next review. Miss it, and it comes back soon. Nail it with confidence, and you won't see it for days or weeks. The result: you memorize hundreds of moves with minimal effort. ChessNotes implements FSRS-5, the same algorithm used by serious study apps, tuned for the chess domain.

FSRS (Free Spaced Repetition Scheduler) is an open-source scheduler that Anki offers as an alternative to its older SM-2 algorithm. Instead of a flat schedule, it estimates for each position how well you know it (stability and difficulty) and brings it back just before you are likely to forget it. For chess this matters: variations have very different difficulties. The aim: fewer pointless reviews and better long-term retention.

Yes. Connect your chess.com or Lichess username (public games only, no password) and ChessNotes groups your games by opening and colour, gives each named variation you play its own repertoire, and builds each tree from the moves you really play and the replies you really meet. Stockfish then checks your habitual moves, and "Mistakes in your openings" (in the account menu) goes through the opening moves of your recent games. One click puts a fix in your tree and at the front of your next review.

Three ingredients: a clear repertoire, a drill system, a feedback loop. ChessNotes covers all three. Build the tree, drill it daily with the spaced repetition engine (single positions, or whole lines from the first move), then correct the real mistakes from your chess.com and Lichess games. That's it — no 400-page books, no PGN files scattered across folders. One place, browser-based, works anywhere.

No. ChessNotes runs entirely in the browser: Stockfish 19 via WebAssembly, Lichess cloud eval when available, Firebase for syncing your repertoire across devices. Open chessnotes.app, create a free account, build or import a repertoire, start drilling — a short guided tour with a getting-started checklist walks you through the first steps. Works on desktop and mobile. No app store, no setup. Being a web app, updates happen automatically.

Yes. There is no paid plan, no cap on repertoires, variations or drills, and no credit card. The whole thing — visual editor, FSRS-5 spaced repetition, in-browser Stockfish 19, Lichess and PGN import, repertoires and mistake checks from your Chess.com and Lichess games — is yours at no cost. It's an independent project running on minimal cloud costs. The core is free today and I intend to keep it that way.

Roughly 1200 ELO and up. Below that, structured opening study has limited payoff — tactics and fundamentals matter more. From 1200 to 2200 ChessNotes is in its sweet spot: build a real repertoire, memorize it with FSRS, correct mistakes game by game. Above 2200 it stays useful as an organization and drilling tool, alongside coach work.

It works on mobile with a layout tuned for small screens: a bottom action bar gives you the board, both training modes, your notes and your library, and the tree adapts to touch. Fully offline isn't available yet — you need a connection for sync and Stockfish cloud — but the app is light and runs fine on 4G. We're evaluating a full offline mode for the future. For now, all you need is a browser tab and 5 minutes a day to see real progress.

Yes, two ways. Lichess study import is instant: open New repertoire, search by name or paste a link and ChessNotes reads every variation, annotation and sideline. You can also import any standard PGN file — repertoires exported from Chessable, ChessBase, SCID or anywhere else. No lock-in either way: what you build stays yours, exportable back to PGN any time.