Is coasting in neutral better than coasting in gear? (For gas mileage)

In my head, it would make sense (when safe to do so), to pop into neutral and just brake to slow down, in order to save gas. The RPMs stay low, right?

I saw a comment on a post the other day saying that coasting in gear saves gas.

My first question is: when coasting in gear, even if RPMs are 3K+, can the car really save gas? And second: is coasting in neutral more or less fuel efficient than coasting in gear?

Thanks!