Please fill all empty fields in such a way, that the numbers from 1 to 9 are unique in every row, every column and in every 3x3 square. For each Sudoku puzzle there is exactly one solution. "Check" validates your input without uncovering the whole solution. "Solve" displays the solution and quits the current game. "New" generates a new puzzle for selected level (1 to 10).

Further information about Sudoku puzzles can be found at http://en.wikipedia.org/wiki/Sudoku.