Sudoku Online
About the game
The classic grid, with new constraints
Sudoku Online starts with a familiar idea: fill the grid so that each row, column and box contains no repeated numbers. Choose from four classic difficulty levels and work from the obvious cells towards the less visible connections.
For a change of pace, try X-Sudoku, Windoku, Killer or Kropki, each with additional constraints to consider. Pencil notes let you keep possible numbers in a cell while you reason through the grid. History and statistics give you a way to look back at your results.
- Four classic difficulties
- Choose a level to suit your mood and the time you want to spend on a puzzle.
- More ways to solve
- X-Sudoku, Windoku, Killer and Kropki introduce different links and restrictions.
- Pencil notes
- Record candidates in each cell and narrow down the possibilities step by step.
- Results and community
- View your history and statistics, compare leaderboard results and join the chat.
What changes in the Sudoku variants?
Classic Sudoku keeps each number unique in every row, column and box. X-Sudoku adds the two main diagonals; Windoku adds highlighted regions; Killer uses sums in cages; and Kropki adds relationships between adjacent cells.
Inside the game
Good games bring people together.
Let’s meet at a conference — or start a conversation here.