Sudoku Online

Sudoku Rules

• Fill the 9x9 grid with digits from 1 to 9.
• Each row, each column, and each 3x3 block must contain the digits 1 to 9, without repeating any number.

Tip: Use logic, not guessing, to solve the puzzle. Start with the easiest cells and progressively work your way through!

Sudoku Solving Tips

1. Start by examining what you already have

Carefully check the digits already given and see if there's a cell that can immediately be filled because no other digit is possible.

2. Use elimination

If a digit already appears in a certain row, column, or 3x3 block, you can exclude it from other cells within the same row, column, or block.

3. Make pencil notes

Lightly write down potential digits in cells where you're uncertain. This helps you keep track of possibilities and avoid mistakes.

4. Look for hidden singles

Sometimes a cell might seem to have multiple options, but upon closer inspection, you'll notice that one digit can’t be placed anywhere else. This is called a hidden single.

5. Think ahead, but don't guess

Logically think ahead about the consequences of placing a digit in a certain cell. If it leads to a contradiction, you'll know you must choose another option.

6. Regularly check your progress

Frequently verify whether each row, column, and block still follows Sudoku rules. This helps you catch and correct errors early.

Enjoy, and happy puzzling!