Free chess tools for analysis, FEN, Elo and PGN
All six tools run in your browser: analyze a position with local Stockfish, rebuild it piece by piece, test a candidate before the engine answers, do the rating math, filter a PGN, or read a whole set of your games in Mega Chess Analysis. No account, no uploads.
All six tools
Pick the tool by what you have in hand: a position, a move to check, two ratings or a file of games.
Chess Analysis Board
Play legal moves, load FEN or a PGN main line, and read the engine's candidate lines at the depth you set.
- Search depth 10–22, you choose
- 1–3 principal variations side by side
- FEN and PGN import
Chess Board Editor
Place pieces by tap or drag, set all six FEN fields, then pass the exact same board into analysis or the Chess Next Move Checker.
- Checks kings, pawns and castling rights
- Side to move and move counters included
Chess Next Move Checker
Build a legal line for both sides, then compare its first decision with Stockfish without live engine output.
- Engine stays hidden until you commit
- Legal moves only, no typos counted
Chess Elo Calculator
Expected score, rating change and a multi-game tournament total, with the standard Elo formula visible line by line.
- K-factor 10, 20 or 40
- Single game or tournament batch
Chess PGN Filter
Keep games by player, result, color, rating, date or ECO code, then copy or download the original matched set.
- Parses the file on your device
- Export keeps the original PGN text
Mega Chess Analysis
Paste a PGN or give your Lichess or Chess.com username. The report reads your recent games, ranks the leaks that cost you points and pairs each one with the drill that fixes it.
- One game or up to 300 at once
- Lichess and Chess.com username fetch
- Every chart ends in a drill, puzzle set or trainer
Compare the six chess tools
Which tool to open depends on what you have in hand.
| Chess tool | What it does | When to open it |
|---|---|---|
| Analysis board | Plays legal moves and shows Stockfish candidate lines at the depth you set, 10 to 22. | One critical position from a game you just played. |
| Board editor | Places pieces by tap or drag and checks all six FEN fields before export. | You have a diagram or a FEN, not a game. |
| Chess Next Move Checker | Lets you calculate legal replies for both sides, then compares the first move with Stockfish. | Checking one decision from a study position. |
| Elo calculator | Computes expected score and rating change with the formula shown line by line. | Before or after a rated game or a tournament batch. |
| PGN filter | Keeps games by player, result, color, rating, date or ECO code and exports the matched set. | Cutting a big PGN down to the games that matter. |
| Mega Chess Analysis | Reads your recent games, ranks the leaks costing you points and attaches a drill to each. | After a batch of games, when one position is not enough. |
After a game
Use only the tool you need at each step.
- Filter the relevant games. Keep one opening, color or rating band in the PGN filter.
- Rebuild the critical position. Paste its FEN into the board editor, or play to it on the analysis board.
- Check your decision. Calculate first in the Chess Next Move Checker, then reveal Stockfish.
FAQ on Chess Tools
Privacy, shared positions and choosing the right tool.