

1. This is a free sudoku solver.
Click a blank square or a red number square to insert, delete, or add a number.
If you click a blank square or a red number square, a popup will appear.
The white numbers in the popup are the numbers not in the clicked square.
The red numbers in the popup are the numbers written in the clicked square.
If you click a white number, the number will be written to the clicked square.
If you click a red number, the number will be erased from the clicked square.
The number you've chosen will appear red in the square.
If you have typed in all the numbers from a sudoku problem in a newspaper, or in an internet page,
then you can click the leftmost button or key in Enter or AltC to see the solutions right now. 2. If the sudoku has many solutions, or is broken, each solution will be displayed one by one. 3. If you want to type another sudoku in the board to cheat the sudoku, then you can click the rightmost button or key in AltL to clear all the numbers of the board. 4. If you want to solve the sudoku from your newspaper or an internet page at this page on your own checking the lapse time, you can type in all the numbers and click the middle button or key in AltT to reset the timer. If you have written all the right numbers in all the squares, the timer will stop and the board automatically tell you that you've solved it showing the elapsed time. 5. Space key will press the button which has the focus. The Focus can be changed by Tab key or ShiftTab key forth and backward respectively. 
