Sudoku

Click a square, then type a digit or use the number pad — 1 through 9, no repeats in any row, column or 3x3 box. Backspace or Delete clears a square. Turn on Notes (or press N) to pencil in candidates instead of a final answer; a definite entry clears them. Squares that repeat a digit in their row, column or box are marked, so a mistake never hides for long. Your game and best time per difficulty are saved in this browser.