PawnbaseChess Trainer

Pawnbase — the honest chess trainer

Theory, made instinct.

Drill the openings you actually play, review every game with a real engine, and turn the mistakes you repeat into practice. Puzzles, repertoires, analysis and spaced repetition — all in your browser, no fog, no invented numbers.

Start training
An account is required — it's what keeps your training in sync across devices.

Assembling: Adolf AnderssenLionel Kieseritzky, London (casual game), 1851

23. Be7#The Immortal Game — really analysed, below
curated puzzles
59,800
grandmaster games
9,294
engine opponents
12
themes
8
C60 Ruy LopezB90 Sicilian NajdorfD37 Queen's Gambit DeclinedE60 King's IndianC02 French AdvanceB12 Caro-Kann
A10 EnglishD02 London SystemC50 Italian GameB01 ScandinavianE20 Nimzo-IndianC36 King's Gambit

Memorising forty moves isn't preparation.

Understanding twelve is.

Every feature in Pawnbase exists for that trade — fewer moves, deeper roots. Ideas first. The moves follow on their own.

The trainer

One board. Everything around it.

Pawnbase
Line 3 of 12
Ruy Lopez · C60main line
1.e4e52.Nf3Nc63.Bb5
+0.3 · book
Why 3.Bb5? It puts the question to the knight that holds e5. Nothing is won yet — 4.Bxc6 dxc6 5.Nxe5 lets Qd4 regain the pawn — but every White plan in the Ruy grows from this pressure.
HintWhy this move?Your move

One login, the whole training suite

Everything here ships today. Nothing is a waitlist, an upsell or a coming-soon tile.

Daily Workout

One balanced session that blends puzzles, repertoire reviews and blunder drills — with a streak you can bank freezes against. Open it, follow it, come back tomorrow.

59,800 puzzles

Rated solving that tracks your rating, 3-minute Storm, themed sets by motif, mate pattern or endgame, a daily puzzle, and a smart mix that picks for you.

Analysis & game report

Eval bar, multi-line search and a full review: accuracy and ACPL per side, move-quality breakdown, phase accuracy and the critical moments. Import from Lichess, Chess.com or a PGN file, and Insights turns the pile into strengths, weaknesses and progress over time — computed from your games, not from a guess about your level.

Fix your blunders

The blunders and mistakes found in your own games become spaced-repetition drills — up to a dozen per game, worst first — repeated on schedule until the pattern is second nature.

Play the engine

Full games against twelve opponents from 600 to full Stockfish strength, each with its own style — pick a colour and play.

Openings, end to end

Walk any position in the explorer with real game statistics, save the lines you like, drill them with FSRS spaced repetition, and scout an opponent's games before you sit down. Gap detection compares the repertoire against what you actually played.

The gym

Guess-the-move over 9,294 grandmaster games, deep-calculation lines you must work out to the end, board-vision drills against the clock, endgames against flawless tablebase defence — and studies to keep your ideas in.

Work with a coach

Redeem the code your coach gives you, then open your games to them one at a time — you grant, they never take, and a note stays private until you mark it shared. Either of you can end the link, which drops every share at once; what it cannot do is reach a copy already downloaded. Needs the cloud backend.

Insights

See exactly where it slips.

No mystery scores — counts, squares and moves, each one traceable to a real engine line. This panel reads the committed review of the Immortal Game; import your own games and the app draws yours.

One famous game, honestly analysed

Adolf AnderssenLionel Kieseritzky, 1851
2501250move 5101520no cp?? 18. Bd6 · −226cp?? 18… Bxg1 · −232cp# 23. Be7# · mate

Centipawns lost per move, 44 of 45 moves measured (line clips at 250cp), from one real run of Stockfish 18 Lite WASM at depth 18. History gives 18.Bd6 two exclams; the engine charges it — both claims are shown, that's the point. 20… Na6 has no centipawn value — a forced mate crossed the ledger — and is drawn as a dashed gap, not as zero.

Where the heavy moves landed

destination squares · one game
abcdefgh

13 of 45 moves lost ≥50cp; their 13 destination squares are shown, dot area ∝ count. Squares no heavy move reached stay empty — an empty square is a fact here, not a zero standing in for unknown.

13 of 45 moves lost ≥50cp
b5 took 2 of the 13 heavy landings
20… Na6 has no cp value — a forced mate crossed the ledger

What analysis looks like

This is a real review by the engine that ships with the app — not a mock-up. Import your own games and every one of them gets this treatment.

Start position · 0/45

Centipawns lost per move, all 45 moves of Adolf AnderssenLionel Kieseritzky, London (casual game) 1851, from one real run of Stockfish 18 Lite WASM at depth 18 on 2026-07-28. 44 of 45 moves are measured (bars clip at 250cp; a 2px tick is a measured zero). 20… Na6 has no centipawn value — a forced mate crossed the ledger — and is drawn as a dashed outline, not as zero.

The method

Fifteen minutes, well spent.

  1. 01

    Create your account

    Google, email and password, or a magic link. The account is what carries your progress between devices.

  2. 02

    Import your games

    Point Pawnbase at your Lichess or Chess.com username, or drop in a PGN. It reviews them and finds your recurring mistakes.

  3. 03

    Train the plan

    Open the Daily Workout and follow it: a few puzzles, the repertoire lines that are due, and the blunders you keep repeating.

Why it feels fast

Pawnbase is a local-first app with a real engine on board, not a thin client for someone else's servers.

The engine is on your device

Stockfish 18, compiled to WebAssembly, running in a Web Worker — single-threaded by default, with a multithreaded build you can opt into in Settings. No analysis queue, no server compute, no waiting your turn.

Local-first, so it's instant

Your games, ratings, repertoires and review schedules are written to your browser's own database. Pages read from disk, not from a network round-trip, and keep working offline once loaded.

Sync is always on

The same data is mirrored continuously to your account, so a laptop and a phone stay in step. Row-level security in Postgres keeps every row readable only by you, apart from the individual games you hand to a coach yourself.

Made to sit in all day

Eight complete themes, board and piece sets, tabular numbers, keyboard shortcuts, reduced-motion support, and it installs to your home screen as an app.

Straight answers

  • You play the engine, not other people. There is no online matchmaking or rating ladder against humans.
  • Coaching is 1:1 and invite-based: your coach hands you a code, you redeem it, and you decide game by game what they can open. There is no marketplace, no classroom, no coach directory and no payments — and it runs on the cloud backend, so a local-only build does not have it.
  • Sign-in is required for every feature, because cross-device sync is the point. Only this page is open.
  • Opening statistics and endgame tablebase answers come from Lichess's public APIs, so those two need a connection.
  • This does not replace a desktop engine. Stockfish is the same program, but every position in a review runs under a time budget so the game finishes, and a search cut short reports the deepest line it actually reached. It is here to explain the moves you played, not to settle the position.
  • It does not replace a coach either. It can tell you what keeps happening across your games and hand you the drills for it. It cannot watch you play, ask what you were thinking, or tell you what to do about your next tournament.

Eight themes, one contract

Calm by default. Yours by choice.

Every theme holds the same measured contract — pieces stay legible on every board, in every palette. Try the two Calm faces here; this page follows, and the choice carries into the app.

…and six more in the app:

  • Slate
  • Wood
  • Nord
  • Dracula
  • Solarized
  • High Contrast

Train the mistakes you actually make

Your move.

Create an account, import a few hundred of your games, and Pawnbase will have a plan for you by the time you finish your coffee.

Sign in or create an account Then come back tomorrow — that's the whole trick.Sign-in required · Local-first storage · Export your games anytime