Is a green flag if a guy you just met online replies quickly to your messages?

met a guy online and we’ve been exchanging for a few hours now, and he always replies within 15 minutes, asking questions and answering anything i ask too. we ended the chat saying we’ll meet up sometime (bc we both are not in the same location yet). I don't know, green flag, red flag, smth else?
Is a green flag if a guy you just met online replies quickly to your messages?
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