How to Make a Sudoku Puzzle

The Short Answer

Step-by-Step: How to Make a Sudoku Puzzle

1. Choose a difficulty level Sudoku difficulty is determined by how many numbers are pre-filled in the grid (called "givens") and which solving techniques are required. Easy puzzles have 36–46 givens and can be solved by simple elimination. Hard puzzles have 22–27 givens and require more advanced logic. Most generators let you select easy, medium, hard, or expert — pick based on your audience.
2. Generate the puzzle Open a sudoku generator, select your difficulty, and click Generate. The tool creates a valid, uniquely-solvable puzzle in seconds. If you don't like the particular layout produced, regenerate for a new one — the difficulty level stays the same but the numbers change position.
3. Verify the puzzle Good generators build verification in automatically — they confirm the puzzle has exactly one solution before presenting it to you. If you're using a tool that doesn't verify, run the puzzle through a separate sudoku solver to check. A puzzle with multiple solutions is invalid and will frustrate solvers.
4. Export the puzzle and answer key Most generators export both a blank puzzle grid (for solvers) and a completed grid (the answer key). Download both. If you're building a puzzle book, the answer key section goes at the back — typically one or two solution grids per page to save space.
5. Format for print Export the puzzle as a PDF or image. For a book layout, import the grid image into Canva and add a title, difficulty label, and puzzle number. For a standalone printable, the PDF from the generator is usually ready to use as-is.

Sudoku Difficulty Levels Explained

Every sudoku tool uses slightly different terminology, but difficulty broadly corresponds to the number of pre-filled squares and the solving techniques required:

For a balanced activity book, a mix of easy, medium, and hard puzzles works well. Start with easier puzzles at the front and increase difficulty through the book — solvers who find it too hard early will put the book down.

Sudoku Variants Worth Knowing

The standard 9×9 grid is the most common format, but several popular variants are worth considering for a varied puzzle book:

• Mini Sudoku (4×4 or 6×6): Uses a smaller grid with fewer numbers. Ideal for young children, large-print editions, or quick-solve puzzles where space is limited.
• Samurai Sudoku: Five overlapping 9×9 grids. Very challenging and popular in dedicated sudoku magazines and books.
• Killer Sudoku: Replaces given numbers with "cages" that must sum to a target value. Requires arithmetic alongside logic — good for mixed-skill puzzle books.
• Irregular Sudoku: Uses irregular-shaped regions instead of standard 3×3 boxes. Visually distinct and well-suited to themed books.

Most free generators only produce standard 9×9 sudoku. For variants, dedicated software like Sudoku Maker Pro or Conceptis Puzzles may be required.

Tools for Making Sudoku Puzzles

Tips for Publishing Sudoku Books

• Include a brief how-to-play page. Not every buyer knows sudoku rules. A single page explaining the basics at the front of the book improves the experience for newcomers.
• Batch generate for efficiency. Tools like QQWing can generate dozens of puzzles at once. Generate more than you need, then select the best layouts.
• Large-print sudoku sells well on KDP. A 8.5×11 inch book with one large-grid puzzle per page targets older adults and is a consistently popular low-content book category.
• Always include an answer key. Place solutions at the back, clearly labelled by puzzle number or page. Missing answer keys are a common complaint in negative reviews.

What to Do Next

Once you have your sudoku puzzles ready, here are the most useful next steps: