How can you tell if your followers are real people or just bots/fakes?

[ronswanson]

So, I recently noticed that my follower count jumped a lot after a small promo I ran, but engagement didn’t really change. Now I’m wondering if some of those new accounts are even real. A few have no profile pics, weird usernames, and zero posts. I’m not sure if they’re bots or just inactive users. Is there an easy way to tell the difference? I’d rather clean up my audience than have fake numbers.