ReplayChess

ReplayChess turns chess history into something you play. Choose a legend, open one of their famous games at its critical position, and play it out for real against a friend through a private link, a rated opponent from the matchmaking queue, or Stockfish running in your browser. When the game ends you get a move-by-move comparison with the original: your match rate and the exact move where you diverged.

Inside the app: 50+ legends from Morphy to Carlsen with playable famous positions; a 3,600-entry ECO openings encyclopedia, every line playable from its resulting position; real-time clocks, rating-based matchmaking and tournaments; Stockfish as WebAssembly at four strengths up to roughly 2200; a post-game practice mode; and it installs as a PWA on phones and desktops.

Who it is for: club and online players who follow chess history channels and want to play the positions instead of watching them, coaches who want to hand a student one position and review the result, and developers curious about a real-time multiplayer app built with Next.js 15, React 19, Prisma, Socket.IO and Stockfish WASM.

Free to play with no ads. The Player plan ($4.99/month or $50/year) unlocks the full legend and opening catalogue. MIT-licensed source on GitHub.