Sudoku is a logic-based number puzzle. The goal is to fill a 9×9 grid so that each row, each column, and each 3×3 subgrid contains the digits 1–9 without repetition.
Basic Rules
Each row must contain the digits 1–9 with no repeats.
Each column must contain the digits 1–9 with no repeats.
Each 3×3 subgrid must contain the digits 1–9 with no repeats.
Tips
Start with singles and progress to advanced logic techniques.
Use pencil marks to track candidates and reduce mistakes.