Sudoku Generator
Generate printable Sudoku puzzles with a unique solution — easy, medium, hard or expert — with the answer key.
How to use
- 1Choose a difficulty.
- 2Press New puzzle, then print or copy it. Tick 'Show solution' to reveal the answer.
How it's calculated
A full valid grid is built by randomized backtracking, then clues are removed one at a time, keeping only removals that leave exactly one solution.
Frequently asked questions
Does every puzzle have one solution?
Yes — each removal is checked with a solver, so every puzzle has exactly one solution.
What makes a puzzle harder?
Fewer clues generally means harder: easy puzzles keep about 40 clues, expert ones about 24–28.
Can I solve my own puzzle?
Use the Sudoku Solver tool — paste the grid and it fills in the answer.