With an active puzzle, the objective is to fill in the missing squares in a 9-column by 9-row grid with the numbers 1 through 9. Each column, row, or 3x3 block cannot contain repeated numbers. There are 4 difficulty levels with 2000 puzzles in each level. The app can be played in 24 different languages.
Sudoku puzzle with numbers 1 to 9 on a 9x9 grid.