Staring at a position and asking "what move should I play next?" This free chess helper answers in seconds: paste the position (or the whole game) and Stockfish, running right in your browser, shows the best move, two honest alternatives, and the reply you should expect. Everything is written in words first, notation second, so you never have to decode a line to understand the answer.
For analysis and training. Using an engine during rated online games violates fair-play rules everywhere.
Three things, every time:
Evaluations are in pawns, from the point of view of the side to move. +1.0 means you are better by about one pawn's worth of position; +3.0 usually means a piece is falling; 0.0 is dead level. Small numbers (under about half a pawn) mean the position is close and several moves are fine. Mate scores replace the number entirely: "mate in 3" means the engine has found a forced checkmate in three of your moves, no matter what the opponent does. If the score is negative even after the best move, the best move is still worth knowing: it is the move that makes your opponent's win hardest.
A calculator hands you the answer to one position. But you will never see that exact position again, and in a real game there is no paste button. What actually moves your rating is the pattern behind the move: why the knight belonged on that square, what the threat was, which of your habits keeps creating these positions. That is coaching, not lookup. The BetterChess coach watches you play, explains each position out loud in plain English, and stops you before the blunder instead of grading it afterward. The calculator is the dictionary; the coach teaches you the language.
Paste your position as a FEN (or paste the whole game as a PGN) and press Analyze. The calculator runs Stockfish in your browser with three candidate lines and shows the strongest move in words and notation, for example "Knight to f3 (Nf3)", plus two alternatives and the reply your opponent is most likely to play. Every claim comes from the engine's numbers, nothing is made up.
Yes. Switch to the Paste PGN tab and drop in the game text from any site or app. The tool cleans up comments and variations, tells you how many moves it loaded, and analyzes the final position of the game, which is exactly the "what move next" moment you pasted it for.
Stockfish, the strongest open source chess engine, compiled to WebAssembly and running entirely in your own browser. Your position never leaves your device: there is no upload, no account, and no server doing the thinking.
Yes, completely. No sign-up, no daily cap, no locked depth. The paid BetterChess product is different in kind: a live coach that talks you through your own games as you play them and stops you before the blunder. The calculator stays free either way.
Related: Free chess game review · PGN roast · AI chess coach · Chess openings explained
BetterChess is a practice tool: we make no guarantee you'll reach 1800 or any rating. Improvement depends on your own practice and effort. Engine analysis powered by Stockfish.