How offline analysis works
Stockfish runs on your device via WebAssembly—no cloud, no queues, no internet needed after setup.
Open Chessomy
Visit chessomy.com in any modern browser (Chrome, Firefox, Safari, Edge). No download required.
Install as PWA (optional)
Use your browser's "Add to Home Screen" or "Install app" option to install Chessomy like a native app.
Analyze your games
Import games by username or paste a PGN. Stockfish analyzes each move locally—no server call needed.
Go offline
Your analyzed games, blunder puzzles, and stats are stored in your browser. Access them anywhere, even without Wi-Fi.
Built for local-first use
Stockfish 17.1 WebAssembly
The full Stockfish engine compiled to WebAssembly runs inside your browser tab at full strength— no server-side compute, no rate limiting.
localStorage persistence
Analyzed games, blunder puzzles, and your username are stored in your browser's localStorage. They survive page refreshes and browser restarts—no cloud sync needed.
Installable PWA
Install Chessomy as a Progressive Web App to get a home screen icon, full-screen mode, and pre-cached assets for instant offline access.
Frequently asked questions
How does Chessomy work offline?
Chessomy is a Progressive Web App (PWA). After your first visit, the app shell, Stockfish WebAssembly binary, and your analyzed games are cached locally. You can revisit and reanalyze stored games without any internet connection.
Do I need to install anything?
No installation is required. Chessomy runs in any modern browser. Optionally, you can install it as a PWA from your browser menu, which gives you an app icon and full-screen experience.
What requires internet?
Fetching games by Chess.com or Lichess username requires an internet connection to reach their APIs. But if you paste a PGN directly, or work with games you've already imported, the analysis is entirely offline.
Does Stockfish really run locally?
Yes. Chessomy uses the stockfish.js WebAssembly build, which runs entirely in your browser. At no point does your position or PGN leave your device for analysis.