Sudoku Rules

• Each row must contain the numbers 1-9, without repetition.
• Each column must contain the numbers 1-9, without repetition.
• Each 3x3 sub-grid must contain the numbers 1-9, without repetition.

Keyboard Instructions

• Press and/or hold (1-9) or these keys to input numbers:
  q

  w

  e

  a

  s

  d

  z

  x

  c
• n - Toggle notes mode.
• u - Undo a move.
• Backspace - Clear a square.
• hjkl (vim) or arrow keys - Move around the board.
• Shift - Temporarily toggle notes mode when held down.
• Meta key (⌘ Mac / ⊞ Win) + click - Select multiple squares for adding notes.