Optionally, spray or brush your air fryer basket with a bit of oil (not cooking spray) to avoid sticking. Then, add the frozen French fries straight from the freezer. Fill up to half the basket in total (they don't have to be in a single layer).
Air fry the frozen fries for about 15 minutes at 400ºF/200ºC. Shake the basket every 5 minutes and keep an eye on them in the last few minutes.Depending on the type of fries and your air fryer, the cooking time may vary (see the Notes below)
Once air-fried, lightly season the fries with salt (to taste) or your choice of seasoning. Then enjoy with your favorite dip!
Notes
How long to air fry different types of fries?
Sweet potato fries: Usually require an extra 2-4 minutes.
Steak fries/Crinkle-cut fries: Usually require an extra 2-4 minutes.
Waffle fries/Lattice fries: 10-12 minutes in total.
Curly fries: Usually take a similar time, around 14-16 minutes.
Shoestring fries: 7-10 minutes in total.
How to store? Like most fries, these air fryer frozen fries are best when enjoyed immediately after cooking. But, if you have any leftovers, store them in an airtight container in the fridge for 3-4 days. Reheat them in the air fryer (about 5 minutes at 400ºF/200ºC) to bring back some crispiness.