ChessUMI

ChessUmi / three free chess apps

Study, train, and analyze locally.

All ChessUmi apps are free. Reading, training, and analysis run locally on your device.

Reader and Tactics offer optional cloud libraries and sync, currently available only to beta testers. Download app and engine files first for offline use; imports from online services and sync need internet.

01 Chessbook ReaderPDFs → positions 02 Tactics TrainerPGN → practice 03 Chess AnalysisPGN → deeper review

01 Chessbook Interactive Reader

Make every chess PDF interactive.

Open a chess book, detect its diagrams, rebuild the positions, and explore them on a real board without leaving the page.

Open Reader
Chessbook Interactive Reader showing a chess PDF alongside its detection and board analysis tools.
From printed diagram to playable position.

What it does

Free · Runs locally

  • PDF workspace

    Open a chess PDF in the browser, navigate its pages, and resume at the last page you studied.

  • Automatic board detection

    Scan document pages for chessboards and turn clear diagrams into reconstructed positions.

  • Book-specific calibration

    Save representative board contours, then train and publish recognition models for a book’s layout, squares, and pieces.

  • Detection review

    Review results, adjust clipped or skewed contours, and correct the side to move or board orientation.

  • Interactive analysis board

    Explore legal moves, edit pieces, flip the board, and apply or copy FEN positions.

  • Local Stockfish

    Analyze with Stockfish 17.1 using an evaluation bar, principal variations, multiple lines, and configurable engine settings.

  • Practice and move review

    Practice either side, inspect the move list, jump through the move tree, and study alternate lines.

  • Comments and study records

    Save notes for a document or position, build study lines, and copy saved studies as PGN.

  • Optional cloud library

    Keep PDFs and book state in an account library with sync and daily snapshots; EPUB/DJVU conversion is available for cloud books. Currently available only to beta testers.

02 Chess Tactics Trainer

Build the tactics course you want to repeat.

Bring your own PGN, choose a training rhythm, and turn every position into measurable practice.

Open Tactics
ChessUMI Tactics showing a populated training board, puzzle controls, and review notes.
Your positions, your pace, your progress.

What it does

Free · Runs locally

  • Bring your own material

    Upload or paste PGN, import shared PGN files on mobile, and choose how titles, moves, and comments are kept.

  • Chessable-aware importing

    Use automatic, standard, or Chessable course-export parsing with duplicate and invalid-record handling.

  • Lichess studies

    Import a public study or chapter from a URL or study ID. Private and unlisted studies need cloud access, currently available only to beta testers.

  • Lichess puzzle themes

    Search themes, choose a batch size, and create a course from randomly selected Lichess training puzzles.

  • Five training modes

    Normal for standard solving, Woodpecker for full-course cycles, Rush for timed runs, Repetition for spaced review, and Blindfold for memory training.

  • Focused puzzle controls

    Use hints, show the answer, skip or reset, advance automatically, and optionally analyze a position with local Stockfish.

  • Timers and mode rules

    Set countdown timers, rush fail limits, woodpecker cycle timers, and per-card repetition timers.

  • Force calculation (Normal only)

    Train calculation under pressure with a configurable timer for each move.

  • Alternative move validation (Normal only)

    Let local Stockfish check alternative moves and accept strong continuations beyond the authored solution.

  • Blindfold and repetition tools

    Memorize with a preview countdown and hidden pieces, or work through due cards with adaptive or fixed-ladder scheduling.

  • Course overview and management

    See every puzzle on a progress map, replay positions, clone full courses or mistakes, configure modes, reset, and delete.

  • Progress and analytics

    Track completion, accuracy, solve speed, mistakes, timing, mode results, and trends stored on your device.

  • Personal settings

    Customize board size and theme, coordinates, light/dark appearance, sound feedback, auto-next behavior, and mode defaults.

  • Optional cloud sync

    Link courses to a cloud library, sync progress across devices, and restore course snapshots without giving up local use. Currently available only to beta testers.

03 Chess Analysis

Turn every game into a study you can continue playing.

Analyze games, explore variations, and continue any selected position on the main board. Review the critical moments with local engines and a library that stays on your device.

Play against computer Open Analysis
Chess Analysis showing a chessboard, a sample game, and variations that can be continued on the main board.
Games, positions, variations, and computer play in one local workspace.

What it does

Free · Runs locally

  • Local library

    Save and resume games, studies, notes, and review results on your device.

  • Moves and variations

    Navigate, autoplay, flip, branch, undo, and redo moves and variations.

  • Annotations

    Add comments, private notes, move symbols, colored arrows, and circles.

  • Position editor

    Place pieces, edit FEN, choose the side to move, and set special-move rights.

  • Imports

    Import single- and multi-game PGN files, plus supported public Lichess and Chess.com games.

  • Local Stockfish

    Use live evaluation, multiple lines, and configurable engine profiles and settings.

  • Game review

    Compare best and played moves, assess quality and turning points, get tactical explanations, follow a guided review, and resume analysis later.

  • Local Maia

    Explore human-style predictions, alternatives, probabilities, predicted outcomes, and rating conditioning.

  • Continue on the main board

    Select a position from a game or variation, then continue it on the main board and save the game to review later.

  • Play Maia your way

    Set an opponent rating target and choose whether you play White or Black. Maia aims for human-like play; its rating is a human-play target, not a measured Elo.

  • Blindfold choices

    Play in Normal mode, with Hidden pieces, Dots, Dots by color, or a Timed reveal of the position.

  • Timed reveal previews

    The first preview lasts 10 seconds. After that, previews repeat every 3 moves per side by default; choose any interval from 1 to 20 moves per side.

  • Sharing and exports

    Create position and study links, export full-variation PGN, and back up or restore JSON.

  • Offline use

    Study and engine analysis work offline after the required app and engine assets have been cached.

  • Free encrypted device sync

    Sync eligible locally created studies by QR or one-time code. Saved studies are encrypted on devices before transfer and the relay cannot read them; encrypted transfers are temporarily buffered and expiring usage records are retained. Imported games stay local, and ten new studies are allowed per public IP in each rolling 24-hour period.