Sudoku

About the game

Sudoku is a logic game you play in your browser: fill the 9×9 grid with numbers from 1 to 9 so that none repeats in any row, column or 3×3 box. Every puzzle is generated on the spot and has a single solution, so you can always reach the answer by deduction, without guessing.

There are three difficulty levels, which change how many cells come filled in: the target is 38 clues on easy, 30 on medium and 25 on hard. Medium is the default level, and the game shows how many clues the puzzle you got actually has.

Your result is your time in seconds, and less is better. The Hint and Check buttons are there to help, and the game highlights numbers repeated in the same row, column or box. Like a brain teaser? Also see the other puzzle games.

How to play

1. Pick the level under Difficulty (Easy, Medium or Hard). Changing the level generates a new puzzle.
2. Click an empty cell. Its row, column and box get highlighted.
3. Enter a number from 1 to 9 on the keyboard or use the number buttons below the grid. Backspace, Delete or the erase button clear the cell.
4. The arrow keys move the selection. Cells that came filled in cannot be changed.
5. Hint fills a cell with the correct value. Check marks the wrong numbers you entered, without revealing the answer.
6. The puzzle ends when every cell matches the solution, and the time of the match becomes your result.

Game modes

• 1 player. Single player against the clock: time only runs while the match is in progress, and the result is measured in seconds.

Tips

• The game highlights numbers repeated in the same row, column or box, so a conflict shows up as soon as you create it.
• Use Check to find out whether what you have placed so far is right before moving on. It only shows which numbers are wrong.
• Since the solution is unique, there is always a cell that can be solved by elimination. Look first at rows, columns and boxes that are almost complete.

Frequently asked questions