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Select a difficulty level to start playing. All puzzles are free, generated instantly, and have a unique solution.
About 12×12 Sudoku
A 12×12 Sudoku uses numbers 1–12 and twelve 3×4 boxes. Significantly harder than 9×9. All puzzles on SudokuMaster.org are algorithmically generated with a guaranteed unique solution. No registration, no downloads — just click and play.
Other grid sizes
Frequently asked questions
What are the rules for 12×12 Sudoku?
Fill every row, column and box with numbers 1 to 12 so each number appears exactly once. Same rules as classic Sudoku — just a different grid size.
Is there a time limit?
No. There is no time limit. The timer shows how long you have been playing, but you can take as long as you need.
Can I save my progress?
Yes. Your puzzle is automatically saved every 15 seconds. If you close the tab and come back, your progress will be restored.
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Free 12×12 Sudoku — no login, no download, works on all devices.
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