🔢 Sudoku Generator
Generate random 9×9 Sudoku puzzles with adjustable difficulty. Print or download as PNG — all in your browser.
About the Sudoku Generator
This tool generates random 9×9 Sudoku puzzles. A full valid solution is built first using backtracking, then cells are removed to create the puzzle. The number of given (pre-filled) cells controls the difficulty — fewer givens means a harder puzzle.
Difficulty levels
- Easy — 40 given cells. Suitable for beginners.
- Medium — 32 given cells. A standard challenge.
- Hard — 26 given cells. Requires advanced techniques.
- Expert — 22 given cells. For experienced solvers.
How to use
- Choose a difficulty level.
- Select whether to view the puzzle, the solution, or both.
- Click Generate for a new puzzle.
- Click Download PNG to save the image, or Print for a paper copy.
Frequently asked questions
Are the puzzles guaranteed solvable? Yes. Each puzzle is derived from a complete valid solution, so a unique logical solution exists.
Does it run offline? The generator runs entirely in your browser. Once the page loads, no internet connection is needed.
Is every puzzle unique? The generator produces random puzzles each time, so repeats are extremely rare.