Hype Killer
Killer Sudoku: standard sudoku, but the grid is split into dotted cages that each add up to a target with no repeated digit. Every puzzle has exactly one solution and a free, always-correct Hint.
Killer Sudoku: how to play, rules & tips
Play Killer Sudoku free online: a full 9×9 sudoku where the grid is split into dotted cages, and the digits in each cage must add up to the small number in its corner. No sign-up, no download, and a free hint that is always right.
How to play Killer Sudoku
The normal sudoku rules apply. Every row, every column and every 3×3 box must hold the digits 1 to 9 exactly once.
On top of that, the grid is covered by cages drawn with dotted lines. The small number in a cage is its target. The digits inside the cage must add up to that target, and no digit can repeat inside one cage.
Most of our boards start completely empty, so the cage sums are your only clues. Tap a cell, then tap a digit. Use Erase to clear a cell, Reset to start the board over, and Next to move on.
Puzzles, difficulty and hints
There are 10 Killer Sudoku puzzles: 4 easy, 3 medium and 3 hard. Every one has been checked by a solver to have exactly one solution, so you never need to guess.
The Hint button fills in one correct cell whenever you are stuck. It reads the real solution, so it can never lead you astray. Correct cells earn Neons as you go, and a full solve adds a clear bonus that grows with difficulty.
Killer Sudoku tips
- Use the rule of 45. Each row, column and box adds up to 45, so if cages cover a box except for one cell, that cell is 45 minus the cage totals.
- Learn the unique combinations. Two cells that sum to 3 must be 1 and 2; 4 is 1 and 3; 16 is 7 and 9; 17 is 8 and 9. Three cells summing to 6 are 1, 2, 3 and to 24 are 7, 8, 9.
- Single-cell cages are free digits. Fill them first and use them to clear out the rest of their row, column and box.
- When a cage sits inside one box or one line, its possible digits are blocked from the other cells there. Pencil these limits in your head before placing anything.
- Big cages are easier than they look: subtract the digits you already know from the target and see what is left.
Frequently asked questions
Is Killer Sudoku free?
Yes. HypeGameRoom is free: no sign-up, no download and nothing to buy to play. Arcade games reward Neons, a play-only currency that can never be cashed out.
Can a digit repeat inside a Killer Sudoku cage?
No. Digits inside a cage must all be different, even when the cage spans two boxes. The cage also has to hit its exact sum.
How is Killer Sudoku different from regular sudoku?
Regular sudoku gives you starting digits. Killer Sudoku gives you cage sums instead, so you solve with arithmetic as well as the row, column and box rules.
What if I get stuck?
Press Hint. It places one correct digit for free, and you can use it as often as you like.