Integrating a hidden solution
Adding a hidden solution to a word search puzzle is not the easiest feature to implement since we have to work with randomly inserted words by you, the puzzle creator and this leaves random amounts of 'open' puzzle cells.
But, there is hope! The Settings > Hidden solution field has some nifty helper features to put you on the right track and to make sure that the puzzle is solvable. To do this, it coaches you while you are entering the hidden solution.
The hidden solution will either be a perfect fit, or too short, or too long. Whenever it is too short, it will show you which characters could not fit. You can use this info to increase the size of the grid, or by removing a word so that more space is available for the hidden solution. When it is too long, it will mention how many characters your hidden solution needs to add in order for it to fill up all the remaining squares.