What do I do with this?

I don't know if I should consider a friend of mine a "best friend" anymore. Recently, the chats we been having weren't filled with much soul as it used to. It was mostly about school stuff or something unrelated to the topic. I don't feel like we connected well as we did last time. Sure we did had a few laughs or so, but the current interests we have don't match anymore. It's alright to be different, but it doesn't really seemed the same anymore since the two of us weren't in the same class together again. Every time I'd encounter her and we start texting or talking, it feels empty and somewhat drained. I'm not trying to say my friend is boring to me now. I just think that I didn't really felt the same energy as we had before. I don't really know what she really thinks about me now, but this friendship might have became one-sided. I wouldn't want to leave her as a friend, though I don't know if we should still be best friends furthermore.