List the candidates
Select an empty square, turn Notes on and add every number that is still possible in its row, column and 3 × 3 box. Tap a number again to remove that mark.
FREE / NO DOWNLOAD
Pixel Sudoku
Nine rows. Nine columns. One clean solution.
TIME0
FASTEST CLEAR—
STATUSReady
N or Shift+1–9 · U to undo one edit
Press Start to play.
How to use pencil marks in Pixel Sudoku
Look for a single
When only one pencil mark remains in a square, switch Notes off and enter it. A confirmed entry automatically removes that number from notes in the same row, column and box.
Use the keyboard
Press N to toggle Notes without losing keyboard focus on your selected square, or hold Shift while pressing 1–9 for a quick pencil mark. Arrow keys move, while Backspace, Delete or 0 clears the selected editable square. Tab enters the board at the selected square; Arrow keys move within it, and Tab leaves for the other controls. Use Undo last edit or U to restore one entry or note change, including affected peer notes. Time and mistakes are not rewound; Undo is unavailable while paused or after solving. Pause hides values and pencil marks from the board and its accessible cell labels. Returning from a hidden tab stays paused until Resume, which restores the exact puzzle and notes.