Killer Sudoku
Sudoku with cages that must add up — no starting numbers needed.
How to play
- Normal sudoku rules first: every row, column and 3×3 box holds 1 to 9, with no repeats.
- Each dashed cage must add up to the small number in its top-left corner — and a digit can never repeat inside a cage.
- A cage with one square left is the easiest way in: its total minus what you have filled gives you the number.
- Tap a cell then a number, or use the keyboard. Notes pencils in candidates; the Hint explains the next logical step.
What it trains
- Adds mental arithmetic to sudoku’s logic — you are reasoning and adding at once
- Calm by default: no timer, no pressure, no account, and no game over
- The hint teaches the cage technique rather than handing you the answer
Play killer sudoku free online: the usual 9×9 sudoku rules plus dashed cages, each of which must add up to the small number in its corner, with no digit repeated inside a cage. Every puzzle is generated fresh with a single logical solution. Relaxed by default — no ads, no account, no timer and no game over — with pencil marks, large print and a hint that explains the next step instead of filling it in. Start in gentle mode, which shows a few numbers to get you going, or classic mode with nothing but the cages. Plays on phone and desktop.
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