How it works
Type your puzzle's starting numbers into the grid below. "Highlight Next Cell" finds one cell you can fill in right now and shows the logic behind it. "Solve Puzzle" fills in the entire grid at once. Everything runs locally in your browser — no data is sent anywhere.
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Puzzle Grid
Enter the starting numbers from your puzzle. Leave empty cells blank.
* New Game generates a fresh puzzle with a unique solution — its starting numbers are locked so you don't overwrite them by accident. Numbers you type in are shown in black. Numbers filled in by the solver or a hint are shown in the accent colour, so you can always tell your own entries apart from the solution.