The goal
Fill each row, column and 3 × 3 box with the numbers 1 through 9, without duplicates. Original clues cannot be changed.
Logic · 5–15 MIN
How to play ↓Sudoku.
Nine numbers. One satisfying challenge.
Getting your game ready…
How to play: Sudoku
The controls
Select a cell and use the number pad or your keyboard. Turn on Notes for pencil marks. Erase removes an entry; Undo takes back your last action. Check marks errors without solving the puzzle.
A little strategy
Start with an almost complete row or box. Look for the only place a number can go. Every generated puzzle has exactly one solution.
Does every puzzle have a solution?
Yes. Each generated board is checked for exactly one solution. Difficulty changes the number of clues, rather than representing a formal technique rating.
Where is my progress saved?
In this browser’s local storage. It is not sent to a server or synced between devices. Clearing browser data or using private browsing may remove it.
A GUIDE TO KEEP GOING
Read the guide ↗Sudoku for beginners: find what is missing
Sudoku is not an arithmetic exercise. It is a placement problem: where a number can go, and where it cannot.