Sudoku modes: Classic, Diagonal & Killer
Three Sudoku variants, one clean interface. Each mode adds a different kind of constraint while keeping the focus on logical solving. Every mode supports Easy, Medium and Hard Sudoku difficulty, so you can start gentle or jump straight into a hard Sudoku puzzle.
Classic Sudoku
Fill every row, column and 3×3 box with digits 1–9 without repeats. It is the familiar Sudoku format and a great place to start.
Play ClassicDiagonal Sudoku
Diagonal Sudoku, also called X-Sudoku, follows the normal rules plus both long diagonals. Each diagonal must contain 1–9 without repeats.
Play DiagonalKiller Sudoku
Killer Sudoku adds dashed cages. Digits in each cage must add up to its target and cannot repeat within that cage. Killer puzzles begin with only a few given digits, because the cage sums do most of the work, and each puzzle is checked to have exactly one solution. Sudokumee includes a live cage-sum helper with valid combinations.
Play KillerWhich mode should I start with?
New to Sudoku? Start with Classic on Easy. When you are comfortable with singles, try Diagonal Sudoku for extra constraints, then Killer Sudoku when you want a puzzle built on arithmetic as well as logic.
Learn each mode
Read the full guides: Diagonal Sudoku rules and strategy and Killer Sudoku rules, the 45 rule and a cage combinations cheat sheet. New to the game? Start with what Sudoku is and how to play.
Same tools in every mode
Notes, hints, undo and keyboard controls work the same everywhere, and your game in each mode is saved in your browser. Easy, Medium and Hard are free in all three.