9×9 Sudoku

Fill each row, column and 3-by-3 box with the numbers 1 through 9, without repeating a number. Choose easy, medium or hard. Your progress is saved in this browser.

• Enter a number: select a cell, then tap 1–9. Use Erase to remove an entry, or Undo to reverse a move.
• Pencil notes: turn Notes on, then tap numbers to add or remove candidates. Turn it off to enter an answer.
• Fill candidates adds possible numbers based on your current entries. Clear notes removes all pencil marks.
• Check entries highlights mistakes. Hint reveals one correct cell and is counted in your statistics.
• Take a break: pause the timer to hide the board. Each difficulty saves its own puzzle.

Keyboard: 1–9 to enter, arrows to move, N for notes, Backspace to erase, Ctrl/Cmd+Z to undo.