Fill every row, column, and 3×3 box with the digits 1 through 9 — no repeats anywhere.
Controls
Click a cell, then type a number or use the number pad. Backspace or Delete clears a cell. Arrow keys move the selection around the board.
Pencil Notes
Toggle Pencil Notes to jot down candidate numbers in a cell instead of committing to one — useful for working out a tricky corner before you decide.
Check & Hint
Check marks any cells that don't match the solution so far, without giving the answer away. Hint fills in the selected cell for you, if you'd rather see it and move on.
Difficulty
Novice through Master control how many numbers you're given to start — fewer givens, sharper thinking required. Every puzzle is generated fresh and guaranteed to have exactly one solution.