Sudoku Generator (Printable Puzzles)

Print fresh sudoku puzzles at the level you want. Each puzzle starts from a random completed grid; clues are then removed (in symmetric pairs, for the classic look) only while the puzzle still has exactly one solution, and every finished puzzle is checked again before it goes into the PDF. Easy and medium puzzles are also checked to be solvable with basic singles alone, so they never need guessing.

How to use this tool

1. Choose the difficulty and how many puzzles (1 to 6).
2. Choose 1 large or 2 puzzles per page.
3. Optionally enter a seed to be able to make the same puzzles again.
4. Press Calculate and download the PDF; the solutions are on the last page(s).

Formula

Remove a clue (or a symmetric pair) → keep the removal only if the solver still finds exactly one solution (and, for easy and medium, singles alone still solve it)

Givens are a rough guide to difficulty: easy about 40, medium about 32, hard about 28, expert as few as uniqueness allows (usually 22–26). Hard and expert puzzles are chosen so that naked and hidden singles alone are not enough. The minimum for any 9×9 sudoku with a unique solution is 17.

Example

Choosing medium, 2 puzzles, 2 per page gives a 2-page PDF: both puzzles (around 32 givens each) on the first page and both solutions on the second. In the solution grids, the original givens are bold and the filled-in digits blue, so you can check a finished puzzle at a glance.