Sudoku Generator

Generate, play, and print Sudoku puzzles of any difficulty

Timer starts when you click "Start Playing"

Preview

Free Sudoku Generator - Generate Unlimited Puzzles

Create Sudoku puzzles in 4x4, 6x6, 9x9, or 16x16 grids with Easy, Medium, or Hard difficulty. Play online with timer and hints, or print worksheets for classroom use.

Generate Unique Puzzles with Guaranteed Solutions

Puzzle Generator

Our algorithm creates valid Sudoku puzzles with exactly one solution. Choose from 4x4, 6x6, 9x9, or 16x16 grids and Easy, Medium, or Hard difficulty levels. Every puzzle is unique and solvable.

Generate Sudoku
Sudoku puzzle generator interface with grid size and difficulty options

Play with Notes, Hints, Undo, and Error Checking

Online Play

Solve puzzles directly in your browser with a full-featured game interface. Use pencil marks for candidates, get hints when stuck, undo mistakes, and toggle error highlighting. Timer tracks your solving time.

Play Online
Interactive Sudoku game with controls for notes, hints, and undo

How to Use the Sudoku Generator

Generate custom Sudoku puzzles in seconds. Perfect for teachers, students, and puzzle enthusiasts who want fresh challenges every time.

Select Grid Size and Difficulty

Step 1

Choose 4x4, 6x6, 9x9, or 16x16 and Easy, Medium, or Hard difficulty.

Generate Your Puzzle

Step 2

Click Generate to create a unique puzzle with exactly one solution.

Play Online or Print

Step 3

Solve in your browser with game controls or print for offline use.

Why Use Our Sudoku Generator?

Train your brain with logic puzzles

Train Your Brain

Sudoku improves logical thinking, concentration, and problem-solving skills.

  • Develop logical reasoning
  • Improve concentration
  • Enhance pattern recognition

Suitable for All Ages

From 4x4 for beginners to 16x16 for experts, puzzles for every skill level.

  • 4x4 for young learners
  • 9x9 classic for everyone
  • 16x16 for advanced players

Print for Classroom

Generate worksheets with or without answers for teaching and homework.

  • Clean printable layout
  • Optional answer key
  • Great for teachers

Loved by Teachers, Students, and Puzzle Fans

See how educators and puzzle enthusiasts use our Sudoku Generator in classrooms and for daily brain training.

Mrs. Johnson

Mrs. Johnson

Math Teacher

I use this to generate Sudoku worksheets for my students. The 4x4 puzzles are perfect for introducing logic to younger kids, and I can print answer keys separately.

Alex Chen

Alex Chen

High School Student

The note feature and hint system help me learn solving techniques. I started with Easy and now I can solve Hard puzzles in under 10 minutes!

David Miller

David Miller

Parent

A great screen-time activity that actually exercises the brain. My kids compete to see who can finish the daily puzzle fastest.

FAQ

Sudoku Generator FAQs

Common questions about generating and playing Sudoku puzzles

  • Our algorithm first creates a complete valid Sudoku grid, then removes numbers based on difficulty while ensuring exactly one unique solution exists. This guarantees every puzzle is solvable without guessing.

  • We offer four sizes: 4x4 (great for beginners and young children), 6x6 (intermediate), 9x9 (classic standard), and 16x16 (challenging for advanced players). Each uses the appropriate box sizes.

  • Difficulty is controlled by how many cells are left empty. Easy puzzles have fewer blanks and can often be solved with basic techniques. Hard puzzles require advanced strategies like candidate elimination and X-Wing patterns.

  • Yes! Click the Print button to open a clean printable version. You can choose to include the answer on a separate page, which is useful for teachers creating worksheets.

  • Notes let you mark possible candidates for each cell. Press N or click the Notes button, then enter numbers to toggle them as small marks. This is a standard solving technique used by Sudoku players.