To enter a new puzzle click a cell and select a number for that cell.
Enter all the given numbers then click the "Start" button to begin
solving. To work on a sample puzzle select it from the list below.
To work on a puzzle click on a cell then use the yellow box to add or
remove candidates and the blue box to enter a value. The colored
buttons can be used to color cells to assist solving. Use the "Undo"
button to remove your previous changes. If you want help to solve the
puzzle click the "Next" button and the helper will show you a next
Use the "Test" button to make sure the puzzle has a unique solution.
Select Strategies to use.