Here's something that's kind of quirky: Frontier actually has a special bag sizer at the gate to make sure your carry-on fits the bill. If it doesn't fit, you'll have to check it and pay the fee - ouch! It's like a little test for your luggage, and let's hope it passes!
Now, you might be wondering what happens if you have a personal item, like a purse or backpack. The good news is that these are usually free to bring on board, as long as they fit under the seat in front of you. Just don't try to sneak in a giant purse, or you might get caught out!
