Preheat the air fryer: Turn the air fryer to 350F and preheat for 3-5 minutes.
Add the grilled cheese: Place the sandwich on the bottom of the air fryer basket in a single layer and set the timer for 5 minutes keeping in mind that you may not need all of this time.
Flip halfway: at the 2-minute mark, flip the sandwich over and reheat for an addtional 2-3 minutes or until the grilled cheese is warmed through and the cheese is melted.
Remove and serve: Use a spatula to remove the grilled cheese and serve while hot. Enjoy!
Notes
Air Fryer Reheating Tips
Store your grilled cheese in foil or an airtight container to ensure it doesn't lose moisture while in the fridge.
If you have the time, let the grilled cheese sit outside of the fridge for 10 minutes so it's not going right from cold to hot which could cause uneven reheating.
The sandwiches should be placed in a single layer in the air fryer basket to reheat evenly. If you have more than one sandwich, cook them in batches.
If your grilled cheese is getting too crispy for your liking, lower the temperature to 325F and check it after a minute or two.
Reheating times will vary depending on how many sandwiches you are reheating at once as well as the thickness of the sandwich.