I’ve eaten here and other In-N-Outs plenty of times and had no issues . Everything is GF except the buns, so order burgers “protein style” which is a lettuce wrap. So fries and all other items are safe. Cross contamination is the biggest problem here. Ask for separate containers for your burger and glove changes. They do not have a separate preparation area for the food.
— Not very
— No gluten-free information on the menu