What ReplayChess is
ReplayChess is a browser-based chess platform for playing the decisive moments of chess history rather than reading about them. Every famous game has a point where the outcome was decided: Morphy's queen sacrifice at the Opera, Tal giving up a piece for an attack nobody could calculate, Carlsen grinding a rook ending everybody else would have drawn. ReplayChess starts you at that exact position, asks you to finish the game yourself against a real opponent or an engine, and then tells you how close you came to what the grandmaster actually played.
How a session works
Open a legend's page, pick one of their games, and press play from the critical position. Then choose an opponent: a private challenge link a friend can open without registering, the rating-matched queue for a timed game, or Stockfish running as WebAssembly inside your browser at four strengths up to roughly 2200 Elo. Clocks, move list and board update live over WebSockets.
When the game ends you get a divergence report: your match rate against the original moves and the first move where your line and the grandmaster's separated. A practice mode drops you back into the position against the engine as often as you like.
What is in the catalogue
Legends. More than fifty players from Anderssen and Morphy through Capablanca, Tal, Fischer and Kasparov to Carlsen, Caruana, Nakamura and Praggnanandhaa, each with a profile and a set of famous games ready to play from their critical positions.
Openings. An encyclopedia of 3,600+ openings indexed by ECO code, each with moves, diagram and FEN, and every one playable from its resulting position so you practise the middlegames your repertoire actually produces.
Tournaments. A group plays the same set of positions and compares results on a shared table.
Who it is for
Players in the 800 to 2000 range who follow chess history channels, coaches who want to hand a student one position and review the report together, club nights, and developers who want a working example of a real-time multiplayer Next.js app with an in-browser engine.
Pricing and source
Free to play, no ads. A Player plan at $4.99 a month or $50 a year unlocks the full legend and opening catalogue. The code is MIT-licensed at github.com/replay-chess/chess-battle-turbo, built with Next.js 15, React 19, Prisma on PostgreSQL, Socket.IO and Stockfish WASM, and installs as a PWA. Built in public by Rohit Pandit (@anaestheticdev).
