NUMBER PUZZLE
Sudoku
Choose a difficulty
Your progress is saved automatically on this device.
Choose a cell, then enter a number. Use arrow keys to move, 1–9 to enter, M for notes, Delete to erase, and Ctrl or Command plus Z to undo. Tab leaves the board.
Select a cell, then enter a number. Use arrow keys to move on a keyboard.
How to play
Fill every row, column, and 3×3 block so the numbers 1–9 appear exactly once in each.
Duplicate numbers in a row, column or block are always highlighted. Turn on Mistake check (off by default) to also highlight entries that differ from the solution.
Use Memo to keep candidate numbers. Auto Notes fills the candidates for all empty cells and replaces existing notes. Undo restores the previous notes in one action. Your entries and elapsed time are saved automatically on this device.