More than 51000 free Sudoku puzzles, individual interface, 6 difficulty levels.

The game is based on a few very simple rules:

Crossword Sudoku is available even offline.

• Each square must contain one number.
• Only numbers from 1 to 9 can be used.
• Each 3 × 3 field can contain every number from 1
• up to 9 only once.
• Each vertical column can contain each number from 1 to 9 only once.
• Each horizontal line can contain each number from 1 to 9 only once. Sudoku is only solved when each row, column and 3 × 3 field contains every number from 1 to 9 exactly once. In other words, no number can be repeated in any 3x3 field, row, or column.