Sudoku generator
Make printable sudoku puzzles at three difficulty levels, up to six at a time, each with exactly one solution. Answer keys included.
How it works
The generator builds a complete, valid grid, then removes numbers one at a time. After each removal it runs a solver that counts solutions; if a removal would allow a second solution, the number goes back. The result: every puzzle here has exactly one answer, so a careful solver never has to guess.
Difficulty is set by how many numbers are given (40, 32 or 27). Fewer givens generally means more steps of logic.
Questions
Does every sudoku have a unique solution?
Yes. Each puzzle is checked by a solver before it is shown, and rejected unless it has exactly one solution.
Can I print several sudoku on one go?
Choose 2, 4 or 6 puzzles. Each prints on its own page, followed by the solutions.
Is there a large-print sudoku?
Tick “Large print” for bigger digits, or see our ready-made large-print sudoku.