How do you know if a guys into you only through IM?

Answer 1

It's hard to tell for most guys via IM. The only signs that he might show (if any) are general nervousness and awkwardness, like in a real talk with you. You should be able to tell from his writing if he's trying to keep the convo up at all cost but has problems with it. Additionally, he might show signs like never wanting you to go (i.e. going sad when you have to go).

Through IM the easiest way to tell is really asking. You can't do anything wrong with your voice pitch, look or such, so it should be easier. You could for example ask him "hey, do you have a gf btw?" and if he says no, ask him whether he'd like to try dating you.