The goal is to fill the 9x9 grid with numbers from 1 to 9 so that each row, each column, and each of the nine 3x3 subgrids (also called boxes or regions) contain all of the digits from 1 to 9 without repeating any.
Click or tap on a cell to select it, then use the number pad to enter a number or clear it. Fixed numbers (in darker cells) cannot be changed.
Use the buttons to check your solution, get a hint, undo moves, or start a new game.