Free Sudoku Online — Number Puzzles & Real-Time 1v1

What is it?

Fill empty cells without repeating a number in a row, column or 3×3 box. Use pencil notes to track candidates as you practice or compete.

Play free in your browser without installation. Sign in with your GameNow account for practice, matches, rankings and friends.

In the lobby, pick a level under "Today's puzzle" (Easy, Normal, Hard, Expert) and press 'Play' to solve alone. To face a person, choose a duel level and press 'Find opponent'.
Click (tap) a cell or move with the arrow keys, then enter a digit with the number buttons or keys 1–9.
Write candidates as notes (toggle with the Notes button or N, or use Shift+digit). A wrong digit shakes the cell and counts as a mistake.
When solving alone and stuck, Hint (3 per puzzle) shows the technique, the reason and the cells behind it. Apply it or close it.
The puzzle ends when every cell is correct. Solo records your time; a duel records the result.

"Today's puzzle" ranks everyone who solved the same level that day by time. A puzzle solved with hints is not ranked.
Solo only counts mistakes and never ends the puzzle. In a duel, three mistakes lose on the spot.
Solving well in a duel automatically sends sabotage that locks or hides your opponent's cells. You can still write notes in a locked cell.