How do I know if a guy is just bieng friendly or is interested?

I have a friend that I've known for 6 months and everytime we meet he always show me pictures of his family and friends and he keep saying u have to meet my brother and friends or u should come to his city and hangout, he's very open and excited irl it's like he always carry the conversation but online he's totally the opposite it can go days and I don't know how it is with him so he make sme confused sometimes, there is a side of me saying he kinda interested in me since he never mentioned any girl and he's very caring and he remembers the smallest things about me and he's kinda touchy but not in a creepy way, and his childhood friends knows about me and there are many but at the same time since we live in different cities it's hard to communicate with him, it's hard to start a conversation with him online and he makes me confused because he's different irl and online.
How do I know if a guy is just bieng friendly or is interested?
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