The objective of Sudoku is to find the right and unique solution to the puzzle given at the beginning. Fill in empty cells on a 9x9 grid with digits so that each column, row and 3×3 box contains all of the digits from 1 to 9, without repeating.
To set a digit select a cell, then click a number in the numpad bar, use Erase button to clear a cell. You can verify whether a solution is correct with Check button, incorrect digits will be highlighted in red. In case you get stuck in a puzzle use Hint button to reveal the correct digit in the selected cell. Notes mode let you add multiple possible numbers in cells.
You can choose an appropriate difficulty level from Easy, Medium, Hard or Master in the menu bar.