FEN Analyzer — Analyze Chess Positions with Stockfish
April 8, 2026·5 min read
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
- Copy the FEN string — Take the FEN from Chess.com, Lichess, a study board, a puzzle, or your chess software.
- 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.
- 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:
- Piece placement — Ranks 8 to 1 separated by slashes. Uppercase is White, lowercase is Black.
- Active color — w means White to move, b means Black to move.
- Castling rights — KQkq lists available castling options. A dash means none remain.
- En passant square — The target square for an en passant capture, or — if it does not apply.
- Halfmove clock — Moves since the last pawn move or capture for the 50-move rule.
- 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.
FAQ
What is FEN in chess?▼
FEN is a text format that fully describes a chess position, including pieces, side to move, castling rights, en passant information, and move counters.
How do I copy FEN from Chess.com or Lichess?▼
On Chess.com, open the board and use the share menu to copy FEN. On Lichess, open analysis and use the board menu to copy FEN and PGN.
Can I analyze a position without uploading a full game?▼
Yes. Put the FEN into a PGN header and import that PGN. This lets chess.rodeo start analysis from the exact position you care about.
Is FEN analysis free?▼
Yes. Position analysis on chess.rodeo is free and does not require signup.