Skip to content
ChessNarrate LogoChessNarrate.

Analyze your chess games.

Upload a FEN string or paste a full PGN game to step through the moves. Client-side engines do the calculations while the Narrator analyzes the story.

Deep-Dive Chess Analysis with Stockfish & AI Commentary

Optimize Your Strategy & Decode Your Position

Welcome to the ultimate web platform for modern, interactive chess analysis. Whether you are an aspiring amateur building your baseline knowledge or a seasoned tournament competitor preparing opening preparation, improving at chess requires a deep understanding of your mistakes. Traditional chess engines provide raw mathematical evaluations (such as +1.5 or -2.4), but they fail to explain the positional logic behind their calculations. Our platform bridges this gap by combining a powerful client-side chess analysis engine with an intelligent, voice-synthesized AI Narrator. We provide a completely free chess analysis environment designed to help you decode the complexities of the board, analyze move quality, and accelerate your learning path.

The Power of Interactive Chess Analysis Boards

Using our responsive chess analysis board, you can explore lines, test hypothetical variations, and analyze recent online matches. With full support for pgn chess analysis, you can copy and paste complete game records directly into the tool. The engine will instantly parse the game history, populate the interactive board, build a momentum line chart, and step through every move with precise evaluations.

This online chess analysis portal runs entirely in your local web browser. There is no software to download, no sign-ups required, and no hidden subscriptions. You get access to premium features of a professional-grade chess analysis free tool, leveraging Stockfish directly on your device. As you step through your games, the line chart visualizes the swing of evaluation, showing exactly where you held the upper hand and where the game slipped away.

Play Chess Against Computer with Real-Time Stockfish Analysis

Looking to test your skills in real time? Switch to our play mode and play chess against computer opponents. Backed by client-side stockfish analysis, you can configure the engine's skill level to match your expertise, ranging from Easy and Medium up to Hard and Master.

Playing against a computer is one of the most effective ways to build board vision and tactical discipline. Instead of silent calculation, our AI Narrator talks back to you after every turn. If you make a mistake, the narrator will point out what you missed, giving you immediate tactical feedback. If you deliver a brilliant checkmate threat, the narrator will mock the computer's impending doom. This feedback loop makes playing against the computer an engaging, educational experience.

Learn Chess Openings and Build Positional Mastery

Every great chess player starts by understanding the first phase of the game. Our analysis board recognizes standard opening theory and helps you learn chess openings by identifying them as they appear on the board (such as the Fried Liver Attack, Queen's Gambit, or Ruy Lopez). By studying opening theory with real-time engine evaluations, you can understand why certain moves are book recommendations and how minor deviations can compromise your pawn structure or king safety.

Move Quality Classifications

To help you categorize your play, our system uses a comprehensive classification system:

  • Brilliant (!!): Exceptional, unexpected moves that turn the game in your favor.
  • Best Move (!): The top recommendation of the engine that maintains your advantage.
  • Excellent (★): Solid alternatives that keep you in a highly favorable position.
  • Good Move (!): Sound moves that maintain dynamic equality or a slight edge.
  • Only Move (□): The single legal or playable response to escape danger.
  • Unclear (∞): Complex positions where neither side has a decisive advantage.

By reviewing your game statistics, you can pinpoint the frequency of your blunders (??), mistakes (?), and dubious moves (?!), giving you a clear roadmap of what tactical areas to study next. Start analyzing today!

Frequently Asked Questions

Learn More About Chess Analysis, Engine Evaluators, and ChessNarrate

What do the numbers mean in chess analysis?
In chess analysis, the numbers represent the evaluation score, measured in centipawns (where 100 centipawns equal 1 pawn value). A positive score (e.g., +1.50) indicates an advantage for White, while a negative score (e.g., -2.30) indicates an advantage for Black. If the score reads mate threats (like M4), it means forced checkmate is available in 4 moves.
How to read chess analysis?
Reading chess analysis involves interpreting evaluation graphs and move qualities. Look at the evaluation bar next to the board to see who has the advantage. Check the move ratings (like Best Move, Excellent, or Blunder) to see how your moves compared to the engine's top choices. The evaluation line chart shows the flow of momentum over time, helping you identify critical turning points in the game.
What is game rating in Chess.com analysis?
In Chess.com analysis, the game rating (or accuracy percentage) is a score from 0 to 100 that measures how closely your moves matched the engine's top choices. It calculates this using a proprietary formula that correlates move quality classifications with expected performance. A higher rating indicates fewer blunders and a more accurate game.
How accurate is ChessNarrate compared to Chess.com or Lichess?
ChessNarrate runs the official Stockfish chess analysis engine directly in your browser, providing the same professional-grade evaluation accuracy as Chess.com or Lichess. The key difference is our AI Narrator, which translates those cold engine evaluation numbers into natural language critiques, helping you understand the strategic concepts behind the moves.
Can I upload games from Chess.com or Lichess?
Yes! You can easily export any game from Chess.com or Lichess as a standard PGN (Portable Game Notation) file or copy its FEN (Forsyth-Edwards Notation) string. Paste the PGN or FEN text directly into our input box to run a complete analysis.
What makes a chess move a blunder vs a mistake?
In chess engine terms, a blunder is a severe error (typically dropping more than 2.00 pawns of value) that instantly loses material or allows checkmate. A mistake is a moderate error (losing between 0.80 and 2.00 pawns of value) that worsens your position and drops your advantage but doesn't immediately lose the game.
Can ChessNarrate explain openings in simple terms?
Yes! Our AI Narrator recognizes common chess openings (like the Ruy Lopez, Sicilian Defense, or Fried Liver Attack) and provides witty, natural language explanations. Instead of memorizing lines, you learn the core ideas behind opening setups and early development.
How private are my uploaded chess games?
Your privacy is guaranteed. All chess evaluations are performed locally in your browser using client-side Web Workers, and your games are parsed in real time. We do not store, track, or save your chess games on any remote servers.