Killer Sudoku — Play Free Online
Killer Sudoku blends classic Sudoku with a little arithmetic. The grid is split into dotted cages, each printed with a target sum; the digits in a cage must add up to that sum and never repeat, while still obeying the normal Sudoku rule that every row, column and box holds each digit once. Most Killer puzzles start with no given numbers at all — you deduce everything from the cage sums.
How do you play Killer Sudoku?
Start with the small cages: a one-cell cage simply is its sum, and a two-cell cage pins down its options fast (a cage summing to 3 can only be 1 and 2). Use those locked combinations as a foothold, then tighten the rest with the row, column and box no-repeat rule. Once it clicks, the cages carry more information than the handful of clues a plain Sudoku gives you.
Start at 6×6, work up to the full 9×9
A smaller 6×6 has fewer cages and lighter arithmetic — minutes to learn. The full 9×9 is where Killer Sudoku really comes alive. Difficulty is adjustable independently, so beginners and veterans both have a sensible starting point.
Free, no download, on any device
Killer Sudoku plays right in your browser on phone, tablet or desktop. There's nothing to install and no sign-up — the core game is completely free. An account is only needed for the leaderboards.
Killer Sudoku combination calculator
Pick a cage size and its target sum to see every valid digit combination instantly — including 6- to 9-cell cages the printable tables stop short of. Use the filters to keep or rule out specific digits.
Combinations: 1Forced
- 123
Frequently asked questions
What is Killer Sudoku?
Killer Sudoku is a Sudoku variant where the grid is divided into dotted "cages", each printed with a small target sum. The digits inside a cage must add up to that sum and never repeat — on top of the normal Sudoku rule that every row, column and box holds each digit once.
How is Killer Sudoku different from regular Sudoku?
A Killer puzzle usually starts with no given numbers at all. Instead of a few clues, you get the cage sums, so you deduce the whole grid from arithmetic combined with the no-repeat rule.
Is Killer Sudoku harder than normal Sudoku?
It can be, because you combine number placement with a little arithmetic. But smaller grids and easier difficulties make it a friendly place to start, and the same solving logic carries over from classic Sudoku.
Is Killer Sudoku free to play here?
Yes — completely free in your browser, with no download and no account needed.
Can I play Killer Sudoku with friends?
Yes. Killer is one of the modes you can race head-to-head in multiplayer — create a room, share the link, and solve the same Killer puzzle at the same time.
Can I play Killer Sudoku on my phone?
Yes. It runs in any modern mobile browser, so it works on phones, tablets and computers.