How to Play:
– Fill the grid with numbers so that every row, every column and every 3-by-3 box contains the digits 1 to 9, without repeating.
– Type a number directly into a square or drag it in from the right.
– If you have narrowed down the possible numbers for a box, enter multiple numbers in small type. Hold the Alt key on a PC or the Control key on a Mac while typing the numbers. To remove the number, repeat the step.
TIMER: Track your time by clicking “Start.”
UNDO: Click to remove the last number you entered, and the one before, and the one before, …
PENCIL: If you’re not sure about an answer, you can mark it as tentative. Click “Pencil” to insert numbers in light blue, and click again to return to the standard color. Shift-delete removes all light numbers, shift-insert makes them dark.
CHECK: To see how you’re doing, click “Check.” Boxes with incorrect answers will be highlighted in pink. To remove all wrong answers at once after checking, hit the delete key.
1..9: Shows all numbers not yet used in the row, column, or box.
HINT: To find out where the next solvable square is, without being told the answer, click “Hint.”
REVEAL: To find the answer in the square indicated by the hint, click “Reveal.”