Few free screeners have all the variables that you will need to run a thorough stock screen. In fact, you'll often have no choice but to screen on a smaller set of variables. But because it is a smaller set, you'll have to deal with more potential candidates than you otherwise would. That's extra work -- and never any fun.
If you want to do better, you'll (unfortunately) have to pay: The screeners that aren't free have a cornucopia of variables. Examples are the screeners from YCharts (Gold and Platinum) and AAII.
