What are the basic rules of Sudoku?

Fill each row, column, and 3x3 box with numbers 1-9 without repeating any number. Each number must appear exactly once in every row, column, and box.

How do I start solving a Sudoku puzzle?

Begin by looking for obvious placements where only one number can fit in a cell. Look for single candidates in rows, columns, and boxes.

What if I get stuck on a Sudoku puzzle?

If you're stuck, look for hidden singles, naked pairs, or other elimination techniques. Sometimes you need to look at the relationships between multiple cells.

How long does it take to learn Sudoku?

Most people can learn the basic rules in 10-15 minutes. Becoming proficient at solving puzzles takes practice - start with easy puzzles and gradually increase difficulty.

What Is Sudoku?

Sudoku is a logic puzzle. The goal is to fill a 9x9 grid so that every row, column, and 3x3 box contains all numbers from 1 to 9. All without repeating any number in each row, column, or box.

The 4 Golden Rules

Each row must have the numbers 1 to 9
No repeats. Every number appears once.
Each column must have the numbers 1 to 9
Again, no duplicates.
Each 3x3 box must have the numbers 1 to 9
There are nine 3x3 boxes in the full grid. No repeating numbers in each one.
Use logic, not guessing
You should be able to solve a good Sudoku with deduction only. No need to guess randomly.

Helpful Tips To Get Started

Look for easy wins: Start with rows, columns, or boxes that already have many numbers filled in.
Cross-check: If you place a number, check that it doesn't break any of the rules.
Pencil marks: If you're not sure, note possible numbers in a cell to narrow it down later.

Learn Popular Sudoku Strategies

Ready to level up? Learn techniques like naked singles, hidden singles, and more in our Sudoku Strategies Guide.