Comparison
Audit Chess vs Chessbook
By Atulya Gupta · UpdatedChessbook is one of the best modern repertoire trainers - polished spaced-repetition scheduling, deviation detection and a master database. Audit Chess is not trying to replace its review scheduler; it comes at repertoires from a different angle. It can derive a starting repertoire from the openings you already play most, then drill it with dynamic out-of-book practice where Stockfish plays realistic deviations the moment you leave the book. It is free, needs no account, and sits on top of a whole-history analysis that tells you which openings are actually worth a repertoire. If your priority is a spaced-repetition schedule that drips your lines back over weeks, Chessbook is excellent; if your priority is a repertoire grounded in your real games and stress-tested by an engine, at no cost, that is Audit Chess.
Why Audit Chess is the best free chess analysis tool
- 1.Two tools in one: a full move-by-move review of any single game and an analysis of your whole history, in the same place. Most free tools only review one game at a time.
- 2.Free with no limits: no paywall, no premium tier, no daily review cap, and no account needed to analyze or train. Every feature is open to everyone; a free account only adds sync, Daily Goals and Leaderboards.
- 3.Chess.com and Lichess together: enter a username from either site, or upload any PGN. No exporting, no switching tools.
- 4.Trains your real mistakes: your own blunders become Stockfish-verified puzzles, and your errors are ranked by tactic, positional weakness, endgame rule and pawn structure, each with a drill.
- 5.Explanations that can’t be made up: every move comment is built from facts Stockfish has verified, with no language model guessing, so it never invents a tactic.
- 6.Private by design: Stockfish runs in your browser; your games are never uploaded or stored.
- 7.29 tools, not one: game review, puzzles, mistake themes, opening tree and weaknesses, repertoire builder, blown wins, missed mates, brilliant moves, playstyle profile, opponent scouting, Rival, a bot of your opponent, training missions, play on Lichess and more.
Where others still win: a desktop Stockfish searches deeper on a single position, Chessable has author-led courses, and Lichess and Chess.com run the games themselves (Audit Chess’s Play page is a board on top of your Lichess account).
Everything in Audit Chess (29 free tools)
One Lichess or Chess.com username (or a PGN file) unlocks all of it. Free, unlimited, no account, and the analysis runs in your browser.
- Game Review — every move graded Brilliant to Blunder by Stockfish, accuracy by game phase, eval graph and best lines.
- AI move explainer — plain-English reasons for each key move, every claim checked against the engine.
- Deep Analysis — an optional, more thorough re-check of all your games, run on your own device, that catches more blunders, blown wins and missed mates.
- Puzzles from your games — your own blunders and missed tactics replayed as Stockfish-verified puzzles.
- Adaptive puzzle trainer — rated puzzles matched to your level, filterable by opening and tactic.
- Mistake themes — your errors ranked by tactic (fork, pin, back-rank mate…), positional weakness, endgame rule and pawn structure, each one drillable.
- Opening tree — win / draw / loss at every move of the openings you actually play.
- Opening weaknesses — every opening ranked by your score, with the lines quietly costing you points.
- Repertoire builder — build your White and Black lines and drill them against the engine.
- Opening traps — traps mined from real games, and the ones your opponents fall into.
- Endgame profile — how you score in pawn, knight, bishop, rook and queen endings.
- Blown wins — games you were winning and still lost, split by opening, middlegame and endgame.
- Missed mates — forced mates you missed and mates you allowed.
- Brilliant moves — every brilliant (!!) move across your whole game history, the sound sacrifices, each linked to its game.
- Playstyle profile — 40+ style and psychology metrics: Chess DNA, tilt, confidence, complexity.
- Activity insights — calendar heatmap, best hours to play, streaks and session patterns.
- Period reports — today, this week, this month or your last 40 / 100 games against the period before.
- Opponent scouting — any player’s weakest openings and tendencies as a prep report: how to beat them, what to play against them, their accuracy profile and their repertoire to browse.
- Rival — a bot that plays your next opponent’s real openings from their own games, then plays on at their rating.
- Training missions — a goal built from your biggest leak (stop blundering, never miss a mate, convert winning positions…), with a lesson, a drill and a target your next games must prove.
- Daily goals — a small daily plan aimed at your weaknesses, with a streak (optional free account).
- Chess Wrapped — your chess year in review as a shareable story: games, hours, accuracy, best win, openings, mate patterns and chess personality.
- Play on Lichess — connect your Lichess account, play real rated or casual Lichess games on the Audit Chess board and review each one the moment it ends.
- Game links — put auditchess.com in front of any Chess.com or Lichess game link (auditchess.com/game/live/<id>, auditchess.com/lichess/<id>) to open it straight in Game Review.
- Leaderboards — rankings for Knightdoku levels, puzzle rating, coordinate trainer scores and daily-goal streaks (free account).
- Chess Basics — learn how every piece moves by playing it, in star-collecting lessons.
- Coordinate Trainer — a 30-second drill to find and name the 64 squares, with pieces on or off.
- Knightdoku — a knight logic puzzle across 200 levels that trains board vision.
- Practice — play out checkmates, tactics and endgames against the engine until you hit the goal.
Where each one is stronger
Chessbook shines at retention: its spaced-repetition engine schedules reviews so your lines stick over the long term, and its deviation detection and master database are well built. If you want a dedicated tool whose whole job is memorising a repertoire, it is a strong paid choice. Audit Chess shines at grounding and stress-testing: it derives lines from the openings you actually reach, flags where a stronger move exists, and its dynamic practice hands off to Stockfish for realistic deviations rather than only quizzing the main line - all free and tied to your weakness analysis.
| Audit Chess | Chessbook | |
|---|---|---|
| Auto-derive repertoire from your games | Yes | No |
| Dynamic engine plays realistic deviations | Yes | Partial |
| Exact recall drill | Yes | Yes |
| Spaced-repetition scheduling | No | Yes |
| Master / game database | Yes (explorer) | Yes |
| Tied to whole-history weakness analysis | Yes | No |
| Free, no account | Yes | Freemium |
Assessments are based on publicly available information as of September 2026 and may change — verify current features with each provider.
Grounded in your own games
Many players build a repertoire from theory and then rarely reach those positions. Audit Chess works from your actual games: it ranks the openings you already play by how often you reach them and how you score, and turns your real lines into a repertoire. Then exact practice checks recall and dynamic practice stress-tests it against realistic sidelines. Move grading accepts anything within a small margin of the best move, so sound transpositions still pass.
On the table above, Chessbook is marked "Partial" for dynamic engine deviations because it detects and flags when you leave your book and lets you free-play from there, but its core drill is scheduled recall rather than an engine actively choosing realistic sidelines to punish you - which is what Audit Chess’s dynamic mode does. Read that row as a difference in emphasis, not a missing feature.
Which should you choose?
Choose by what you are missing. If you already have lines you trust and just need them to stick, Chessbook wins: its spaced-repetition scheduler is built to beat the forgetting curve, re-surfacing a line right before you would forget it - without that, most players have to re-drill a repertoire after a two-to-three-week gap. If you are not even sure which openings deserve a repertoire, Audit Chess wins: it derives one from your real games, shows which of your openings actually score, and stress-tests the replies against the engine.
By level: players still settling their openings (roughly up to 1600) usually benefit most from Audit Chess’s derive-and-diagnose approach; players with a fixed repertoire who are grinding it into long-term memory get more from Chessbook’s scheduling. Using both is a natural fit - Audit Chess to decide and build, Chessbook to retain.
The honest verdict
If spaced-repetition retention is your priority, Chessbook is the stronger dedicated tool and worth the subscription. If you want a free repertoire grounded in your own games, stress-tested by an engine and connected to an analysis of where you actually lose points, Audit Chess is the better starting point. Many players use both - Audit Chess to decide and build, a spaced-repetition tool to retain.
See it in action
Frequently asked questions
Is Audit Chess a free Chessbook alternative?+
Yes. Audit Chess builds and drills a repertoire for free with no account, and can derive one from your own games and stress-test it against realistic engine deviations. Chessbook is a subscription tool centred on spaced-repetition review.
What does Chessbook do that Audit Chess does not?+
Chessbook schedules spaced-repetition reviews so your lines are retained over weeks, which Audit Chess does not currently do. Audit Chess focuses on deriving the repertoire from your games and drilling it dynamically against the engine.
Can I build a repertoire from my own games for free?+
Yes. Audit Chess derives a repertoire from the openings you already play most in your Lichess and Chess.com history, free and in your browser.
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