A LITTLE FOCUS. A FRESH START.
Play Killer Sudoku
Play free Killer Sudoku online with sum cages and starting numbers. Try five difficulty levels, take notes, and save your puzzle in this browser.
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OneStop Sudoku, wherever you go.
Website saves stay in this browser and don’t transfer to the app.
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The game loads here. Choose a difficulty to start or resume a puzzle.
LEARN THE TWIST
How to play Killer Sudoku
Killer adds arithmetic cages to the normal Sudoku rules. OneStop’s version includes starting numbers as well as cage totals, so you can combine ordinary Sudoku deductions with sums.
The rules
Fill each row, column, and 3×3 box with 1–9, without repeats. Dashed cages add up to their small total. Digits cannot repeat within a cage.
A useful first move
Look for small cages with few possible combinations. Every complete row, column, or 3×3 box totals 45, which can help you work out a cell left outside a group of cages.
A two-cell cage totaling 3 must contain 1 and 2, in either order. A two-cell cage totaling 4 must contain 1 and 3: 2 + 2 is not allowed because a cage cannot repeat a digit.
Controls, difficulty, and saved games
Choose Beginner, Easy, Medium, Hard, or Expert above. Select an empty cell, then tap a number or use your keyboard. Notes let you pencil in candidates; three hints are available. Three mistakes end the puzzle.
Every mode and difficulty keeps a separate save in this browser. You can switch puzzles and return to your place. Clearing site data removes these saves; they do not sync with another device or the iPhone app. Settings include night mode and optional automatic cell advancement.
Correct entries earn points. High scores are stored by mode and difficulty and update only when beaten; completed-puzzle count and day streak are shared.
FIFTEEN WAYS TO PLAY
Explore all Sudoku modes
A familiar grid, a different kind of logic. Every mode is free to play in your browser.