Free · No sign-up · Runs in your browser

Free online chess analysis board

Set up any position or import a game, and get world-class engine analysis on every move - evaluation, best moves, and the reasons behind them.

Open a sample game → Opens Morphy’s Opera Game (Paris, 1858) on the board with the engine running.

What the analysis board does

• Live Stockfish evaluation on every position, updating as you move the pieces.
• Board editor - build any position by hand, choosing whose move it is, castling rights and en passant, then send it to the board.
• Best-move arrows drawn straight onto the board and colour-coded by how good each move is, so you can see the engine's top choices at a glance instead of reading a list of notation.
• Opening explorer - how often each move is played from this exact position, and the win, draw and loss rates behind it.
• Explode the position - show every candidate move and its evaluation at once, for when you want the whole tactical picture rather than the single best line.
• Guess the move - quiz yourself against the engine's choice and find out immediately whether you would have found it.
• Game report - a full pass over a whole game marking every inaccuracy, mistake and blunder for both sides.

It runs in your browser

Stockfish runs locally, in the browser tab, using WebAssembly - your moves are not queued behind other people's analysis on a shared server, and there is nothing to install. On a modern browser the engine uses multiple threads, so analysis depth on a laptop is comfortably beyond what any club player needs.

That also means it works the same on a phone, on a work laptop where you cannot install software, and offline once the page has loaded.

Ways people use it

• Reviewing a game they just lost, to find the move where it actually went wrong.
• Checking an opening line before playing it, using the explorer to see what happens at their own rating rather than at grandmaster level.
• Setting up a position from a book or a video and playing with it.
• Analysing a friend's game together from a shared link.

Keep going

Frequently asked questions