Fill every row, column, and 3x3 box with the numbers 1-9 (or letters A-I in Letters mode) so that no
number/letter repeats within any row, column, or box.
- Select a cell, then tap a number/letter on the keypad below the board to fill it in.
- Notes switches the keypad into pencil-mark mode - taps add or remove small candidate marks
in a cell instead of a final answer.
- Undo / Redo step backward or forward through your recent moves.
- Erase clears the value or notes in the selected cell.
- Hint reveals one correct cell for you - each puzzle has a limited number of hints, and each
one costs points.
- Pause hides the board and stops the timer so you can step away without losing your place.
- Wrong entries are marked as mistakes and cost points every time; the timer also counts down your score, so
faster, cleaner play scores higher.
- A keypad number/letter grays out once all 9 of it are correctly placed on the board.
- Your progress saves automatically - close the page and you'll be offered to continue the same puzzle next
time.
