"lol" if I don't care
"LOL" if its actually funny
This. If I add anymore description, I probably laughed in real life.
Using "lol" though can be in two ways for me.
1) If I use it at the end of a phrase or sentence, it's usually to indicate that I'm either joking or somebody else may find it funny, but I don't.
E.g. "Look at this lol"
2) If I use it by itself, it is usually used as a filler when I want someone else to know I saw what they posted. I also sometimes use it in a condescending form usually to tell that the person I'm directed at is being stupid.
Aye, all these grammar rules for "lol".