ChessAnalysis

A free, browser-based chess.com game review and tactics trainer — the paid "Game Review" and "Puzzles" features, recreated to run entirely in your browser. No premium account, no backend, no sign-in. Hosted on GitHub Pages.

Live: https://danieltomaro13.github.io/ChessAnalysis/

Game data comes from the public Chess.com Published-Data API. Engine analysis uses Stockfish compiled to WebAssembly. Puzzles use the open Lichess puzzle database, plus tactics generated from your own games.

Features

Review

• Look up any chess.com player by username and browse their games by month, with result/color/type filters, opponent search, and a month W/D/L summary.
• Replay any game: board, move list, click-to-jump, keyboard navigation, sounds.
• One-click engine review (single-threaded Stockfish, in a Web Worker):
  • Eval bar, best-move arrows, and a clickable eval graph.
  • chess.com-style move classification with on-board badges — Book, Brilliant, Great, Best, Excellent, Good, Inaccuracy, Mistake, Miss, Blunder.
  • Key moments — jump straight to the turning points.
  • Per-side accuracy % (lichess volatility-weighted + harmonic model) and a rough estimated rating for the game.
  • Both players' profile cards: avatar, title, flag, and current Bullet/Blitz/Rapid ratings.
  • Analysis is cached in IndexedDB, so reopening a game is instant.

Puzzles

• Trainer: 5,769 bundled Lichess puzzles, quality-filtered across rating bands 500–2800. Click-to-move with legal-move hints, tactic-theme filter, personal puzzle rating, streak, and difficulty selection.
• Rush: a 3-minute race — solve as many as you can; three strikes ends it.
• My mistakes: the mistakes and blunders found while reviewing your own games become "find the best move" puzzles, saved per username.
• Stats: level/XP, rating-history sparkline, per-tactic accuracy, and achievements.
• Rewards (XP, levels, streak combos, daily goal, achievements) and all progress are stored in localStorage.

App

• Settings: board themes, default engine depth, sound on/off.
• Sound effects, a mute toggle, installable PWA with a favicon/manifest.

Roadmap

Done:

• Phase 1 — Game viewer

• Phase 2 — Engine review (eval, accuracy, move classification, graph)

• Phase 3 — Puzzles (Lichess trainer + "my mistakes")

• Phase 4 — Game feel: click-to-move with legal-move highlights, in-panel hint / show-solution, move/capture/check/solve sounds (with a mute toggle), tactic-theme filters, and a reward loop — XP, levels, streak combos, a daily goal, and achievements.

• Phase 5 — More tools: game filters + month stats, key-moments jumps, persistent (IndexedDB) analysis cache, settings + board themes, favicon / PWA, Puzzle Rush, and a stats dashboard.

• Phase 6 — Explore & share: drag pieces on the review board to branch into engine-evaluated variations, an offline opening explorer (theory continuations + opening names), clock / time-per-move from the PGN, shareable deep links (games at a ply, and puzzles), and a service-worker that makes the whole app installable and offline-capable.

• Phase 7 — Bring your own game: paste or upload any PGN to review it with the full engine pipeline; an engine multi-line panel; an opening repertoire breakdown (W/D/L per opening, by colour); and annotated PGN export (NAGs + evals).

• Phase 8 — Library & opponents: a saved-games library (star any game/PGN, revisit it from the Saved tab), a head-to-head view (your record vs each opponent, click to filter), and a rating-trend sparkline for the loaded month.

Tech

React + Vite (fully static), chess.js, react-chessboard, and Stockfish.js (WASM).

Engine note: a single-threaded Stockfish build is used on purpose — GitHub Pages can't send the COOP/COEP headers that SharedArrayBuffer (threaded WASM) requires. The engine lives in public/engine/ and runs in a Web Worker; choose Fast/Balanced/Deep search depth before analyzing.

Bundled data assets (regenerated offline, not fetched at runtime): public/openings.json (opening book) and public/puzzles.json (puzzle set).

Develop

npm install
npm run dev      # local dev server
npm run build    # production build into dist/
npm run preview  # preview the production build

Deploy

Pushing to main triggers .github/workflows/deploy.yml, which builds the site and publishes dist/ to GitHub Pages.

One-time setup: in the repo, go to Settings → Pages → Build and deployment → Source and select GitHub Actions.

The site is served from /ChessAnalysis/; this is set as base in vite.config.js. If you rename the repo, update it there.

Suggested GitHub topics

chess · chess-com · chess-analysis · game-review · stockfish · chess-engine · wasm · puzzles · tactics-trainer · lichess · react · vite · github-pages

Disclaimer

Not affiliated with or endorsed by Chess.com or Lichess. Uses only public API data and openly-licensed datasets.