Is there only one solution to every Sudoku puzzle?

A proper Sudoku puzzle has only one unique solution. All the puzzles generated by our tool are valid and have a single solution.

What do the difficulty levels mean?

The difficulty of a Sudoku is determined by the number of given clues and the types of logical techniques required to solve it. "Easy" puzzles can be solved with basic scanning, while "Expert" puzzles may require advanced techniques like "X-Wing" or "Swordfish".

Free Online Sudoku Puzzle Game

How to Play Sudoku

Sudoku is a logic-based, number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 subgrids that compose the grid contain all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a single solution.

Basic Strategies for Beginners

Scanning: Scan rows and columns to eliminate where a specific number can be in a given region. The process is repeated with other numbers.
Cross-Hatching: This involves scanning rows and columns for a particular number to find its location in a single region.
Penciling In: When you're not sure which number to place in a cell, you can write small "candidate" numbers in the corners of the cell. As you place more numbers, you can eliminate candidates until only one remains.

Frequently Asked Questions (FAQs)

How to Play Sudoku

Basic Strategies for Beginners

Scanning: Scan rows and columns to eliminate where a specific number can be in a given region. The process is repeated with other numbers.
Cross-Hatching: This involves scanning rows and columns for a particular number to find its location in a single region.
Penciling In: When you're not sure which number to place in a cell, you can write small "candidate" numbers in the corners of the cell. As you place more numbers, you can eliminate candidates until only one remains.