If you cannot solve a hard sudoku, you can try to do it with the assistant. It will show you the possible options.
Fill the game field in the input mode using the numbers or use the text field below.
Press 1-9 buttons to see the possibilities.
In this mode a double click on a sell fills it with the highlighted value. A right click or a long touch marks the cell as not possible.
Cancel marking button removes your impossible marks.
Find button finds the only possible number (if exists).
Enjoy the game!
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You can also fill the sudoku field with a text line. You can see the format in the tooltip.
Or select one of our hard puzzles:
Are you sure you cannot solve this sudoku? Try the easy way:
Solve it on Andrew Stuart's site (http://sudokuwiki.org)