Classic
Each digit from 1 to 9 appears exactly once in every row, column and 3×3 box.
The free puzzle section
Your Sudoku is waiting.
60 free puzzles. Classic, Killer and Samurai, each across four levels. Choose a square and begin, with a keyboard or a finger.
Variant
Level
Puzzle
Loading puzzle.
With a keyboard: enter digits · Shift + digit for notes · arrow keys to move · Backspace to clear.
The rules, briefly
Killer
The dashed cages add a sum constraint. No digit can appear more than once within a cage.
Samurai
Five overlapping Sudoku. In the shared boxes, a number must fit both grids at once. On small screens you can scroll the large board sideways.
Good to know
Are the browser puzzles really free?
Yes. All 60 Sudoku and 80 logic squares can be played without a purchase or an account. The apps are a separate offer on the App Store.
What is different in the apps?
The browser contains a fixed selection and can reveal cells. Sudoku Pro and Quadrivium generate new puzzles and use their hints to explain the next logical step.
Can I play on my phone?
Yes. Tap a square and use the number buttons below the board. A larger screen is comfortable for the big Samurai grid.