Objective / Rules - Complete the grid such that every row, every column, and every 3 x 3 block contains the digits from 1 to 9. - Every cage has a little clue in the corner, and digits in each cage must add to the clue. - A number cannot appear more than once in a cage (which is different to CalcuDoku). - We have provided a page that shows possible combinations.
Help Read the help page on Killer Sudoku for a more detailed explanation and a walkthrough.
Pencil Marks Enter a single number as an answer. Enter multiple numbers as pencil marks.
Keyboard Usage[only when your cursor is in the grid] Note: not all options work on all browsers. A = auto-pencil marks (or click the check box). P = show a pinned square. CTRL + arrows = move around the grid. SHIFT + number = highlight all squares with that number [SHIFT+0 to clear].
Checking If you click 'Check' the system will tell you to use the 'Show Errors' option to check your solution.
Uniqueness Each puzzle has exactly one solution, which can be found using logic alone and no guesses are ever required. If you think you've found another solution, then please double check the rules.