Sudoku

About the Game

Sudoku is a puzzle on a 9×9 grid divided into nine 3×3 squares. The goal is to fill all empty cells with digits from 1 to 9 so that each digit appears exactly once in every row, every column, and every 3×3 square. Some cells are already filled in at the start and serve as clues — they cannot be changed. The solution is considered correct when the entire grid is filled without repetitions according to the rules.

How to Play

Play Sudoku directly on the website. Various difficulty levels and hints are available.

  • 1
    Start Click the 'Play' button in the main menu.
  • 2
    Entering Numbers Select the desired cell and click on it, then choose a number from the panel below. If the selected number already exists in that row, column, or 3×3 square, it will be highlighted in red.
  • 3
    Pre-filled Cells Cells that are filled in at the start have a slightly darker font. Cells revealed using hints are highlighted in the same tone.
  • 4
    Menu At the bottom of the screen there is a menu with the following buttons: hint, clear cell, undo.
  • 5
    Finish The game ends when the entire grid is filled and no cell is highlighted in red. To start a new game, click the icon in the top right corner next to the timer and choose a difficulty: easy, medium, or hard.

Tips

Try to start with the most filled rows, columns, and 3×3 squares — it is easiest to identify the missing digits there.

Use the 'single candidate' method: if only one digit fits in a cell, go ahead and place it.

If you get stuck, switch to a different area of the grid: sometimes the solution becomes clear after filling in a neighboring square or another row.