Free, private, browser-based
Upload a PGN or paste your moves, then analyze the game here with Stockfish. Your position stays in your browser and the results appear without a page change.
Drag a .pgn file here, or paste the moves below.
Board preview
The analyzer parses your PGN into positions, runs Stockfish WebAssembly locally, and connects each engine score to the matching move. That makes it easy to spot an opening mistake, a missed middlegame tactic, or an endgame decision that changed the result.
Use the depth and variation controls for a quick scan or a more careful review. The board, evaluation, principal variation, and move list remain together so you can test the suggested idea immediately.
Plychess is free to use, does not require an account, and does not upload your game for analysis. It works with a PGN from a recent online game or a position you want to study on your own device.
After a review, continue with the chess board editor, generate a Chess960 position, or use the offline chess board.
An analyzer is the tool that evaluates positions and moves. Analysis is the engine output: scores, principal variations, and candidate moves. A review is the human study step after analysis, where you replay the critical moments and understand why a move worked or failed.