FEN Analyzer — Analyze Chess Positions with Stockfish

Analyze any chess position from FEN with Stockfish 17. Get evaluation, best moves, and a clean PGN template you can import right away.

Analyze Any Chess Position from FEN

FEN (Forsyth-Edwards Notation) describes a full chess position in one line: pieces, side to move, castling rights, en passant square, and move counters.

chess.rodeo does not just display the board. It lets you turn that FEN into a position you can run through Stockfish, review move quality, and continue analyzing from the exact moment that matters.

How to Analyze a FEN Position

1. Copy the FEN string — Take the FEN from Chess.com, Lichess, a study board, a puzzle, or your chess software.
2. Place it into a PGN header — Use the FEN header shown below. You can add moves after the starting position or leave the PGN short.
3. Import it into chess.rodeo — Run Stockfish analysis, inspect best moves, and keep the position as part of your training workflow.

FEN Format Explained

A FEN string has six fields separated by spaces:

1. Piece placement — Ranks 8 to 1 separated by slashes. Uppercase is White, lowercase is Black.
2. Active color — w means White to move, b means Black to move.
3. Castling rights — KQkq lists available castling options. A dash means none remain.
4. En passant square — The target square for an en passant capture, or — if it does not apply.
5. Halfmove clock — Moves since the last pawn move or capture for the 50-move rule.
6. Fullmove number — The current move number in the game.

PGN Template for FEN Analysis

Use this template when you want to analyze a position instead of a full game:

[Event "Position Analysis"]
[Site "chess.rodeo"]
[White "Analysis"]
[Black "Position"]
[FEN "r1bqkb1r/pppp1ppp/2n2n2/4p3/2B1P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4"]

4. Ng5 d5 5. exd5 Na5 *

You can keep the move list short or extend it with the line you want to test.

Related Analysis Tools

• PGN Analyzer — Analyze full PGN files and multi-game exports with Stockfish.
• Chess Accuracy Calculator — See how accurate your moves were and compare results by rating.
• Free Chess Analysis — Compare chess.rodeo against Chess.com and Lichess for free analysis.