Sudoku, all in one.
Play free Sudoku online: Classic, Diagonal and Killer, all in one place. No ads, no pay-to-win, unique-solution puzzles every time.
Play freeThe number in a Killer Sudoku cage is the total of all digits inside it. Use it to narrow down the possible digits.
Three ways to play
Same clean board. Different logic.
Classic
Fill every row, column, and 3×3 box with digits 1–9, no repeats. The version you already know.
Diagonal
Everything in Classic, plus both long diagonals must also hold 1–9 with no repeats. One extra constraint changes the whole puzzle.
Killer
Digits inside each dashed cage must sum to the corner number and can't repeat. Sudokumee shows live valid combinations for the cage you're solving, so you're never guessing blind.
Learn Sudoku
Rules, strategy and cheat sheets for every mode.
What is Sudoku?
The rules and how a puzzle works, in plain language.
Sudoku tips & techniques
From basic singles to pointing pairs, naked pairs and X-Wing.
Killer Sudoku guide
The 45 rule and a cage combinations cheat sheet.
Diagonal Sudoku guide
How the two diagonals change the puzzle, plus strategy tips.
Printable Sudoku puzzles
Print a free set of Classic, Diagonal or Killer puzzles, with an optional answer key.
Why Sudokumee
Built from what the Sudoku community actually asks for.
No ads, ever
No pop-ups, no forced video ads, no interruptions mid-solve.
No pay-to-win
Hints, undo, notes and every difficulty level are free for everyone.
Guaranteed unique solutions
Every puzzle is checked at generation time so there's exactly one valid answer. In Killer, the cage sums are part of that check.
Picks up where you left off
Close the tab and come back. Your puzzle, notes and timer are saved in your browser, one game per mode.
True dark mode
OLED-friendly black, easy on the eyes and your battery.
Explains, doesn't just solve
Hints point you to the next logical step and let you decide whether to apply it. They also flag a wrong digit before you build on it.
Frequently asked questions
Is Sudokumee free to play?
Yes. Every mode, difficulty, hint, and the Killer cage helper are free, with no ads and no pay-to-win purchases.
What is Diagonal Sudoku?
Diagonal Sudoku (also called X-Sudoku) follows normal Sudoku rules, plus both long diagonals of the grid must also contain the digits 1 to 9 with no repeats.
What is Killer Sudoku?
Killer Sudoku adds dashed-outline cages to the grid. The digits inside each cage must sum to the small number in its corner and cannot repeat within that cage.
Does every puzzle have a unique solution?
Yes. Every puzzle is checked at generation time to confirm it has exactly one valid solution before it's given to you. Killer puzzles are checked against their cage sums too.
Can I print Sudoku puzzles?
Yes. Use the printer button on the game board to print your current puzzle, or make a whole set on the printable Sudoku page, with an optional answer key.
Is my game saved?
Yes. Your current game in each mode is saved in your browser, so you can close the tab and pick up where you left off.