Help! Is This Arabic?
This website is well-meaning, but will be difficult to parse if you don't have elementary Arabic and can't tell apart ال from ل    ا.What it really needs is a simple reference input string, examples of how it gets broken, and what to do to fix them.  The middle case, where the sentence is correctly rendered RTL but the individual words are LTR (breaking the ligatures), is particularly common and insidious because it looks plausible to non-Arabic speakers.