Online Chess Board Analysis
Set up any position and analyze it with Stockfish for free. Drag the pieces, paste a FEN, or play through a line and watch the engine evaluation update in real time — the best move, the principal variation and the exact score for both sides.
It works entirely in your browser with no signup, a fast free alternative to 365chess and chessnextmove for exploring positions and openings.
There is nothing to download or install, and it works the same on desktop and mobile. Use it to check an opening line, find the best move in a tricky middlegame, or verify an endgame — the engine searches deep and shows the full principal variation for each side, not just a single move.
What you can do on the analysis board
Live engine evaluation
See Stockfish's evaluation and best move update as you play moves on the board, with a clear eval bar and the top engine lines.
Set up any position
Start from the initial position, drag pieces to build a custom position, or load a FEN to analyze exactly the spot you care about.
Explore variations
Try candidate moves and instantly compare them against the engine's recommendation to understand why one line is better than another.
Opening & endgame ready
Play through an opening to see where the evaluation shifts, or set up a king-and-pawn endgame to check the winning idea — any legal position works.
Depth you control
Watch the search depth climb in real time and compare the top engine lines side by side, so you see the best move and the runner-up, not just one number.
Free and private
Nothing leaves your device. Stockfish runs locally in WebAssembly, so every position you set up stays private — no account, no uploads, no daily limits.
How to analyze a position
Set up the position
Drag pieces onto the board to build a position, or paste a FEN string to load an exact spot you want to study.
Read the evaluation
The eval bar and score show who stands better — a positive number favors White, a negative number favors Black, and near zero is roughly equal.
Follow the best move
The top line shows Stockfish's recommended move and the principal variation for both sides, so you see the whole plan, not just one move.
Explore alternatives
Play a different candidate move to instantly see how the evaluation changes and understand why one line is stronger than another.
Frequently asked questions
Can I paste a FEN to analyze a position?
Yes. Load any FEN and Stockfish will evaluate the position and show the best move, the principal variation and the exact score for both sides.
Is this a free next-move / best-move finder?
Yes. The board shows the engine's best move for any legal position you set up, completely free and with no signup or daily limits.
Which chess engine does the board use?
It uses Stockfish 18, one of the strongest chess engines in the world, compiled to WebAssembly. It runs locally in your browser, so there is no paid account and no server round-trip.
What does the evaluation number mean?
The score is shown from White's perspective in pawns: +1.0 means White is a pawn better, -2.0 means Black is winning by two pawns, and a value near 0.0 is roughly equal. A '#' with a number means a forced checkmate in that many moves.
Can I analyze a chess opening?
Yes. Play through the moves of any opening on the board and watch the evaluation update move by move to see which lines hold the balance and where one side goes wrong.
Does it work on mobile?
Yes. The analysis board runs in any modern browser on phone, tablet or desktop — nothing to install, and the engine runs on your own device.