We may earn a commission from links on this page.It wouldnt be fair to say that I bought an air fryer simply to reheat french fries, but it would be disingenuous to claim that my desire to reheat french fries had nothing to do with the purchase. A few years agowhen we were young and the air was sweetI wrote a blog claiming that waffling sad, cold fries was a first-rate way to reheat them.Almost immediately, the comments started rolling in. You fool, you absolute imbecile, they said. An air fryer is the only tool you should use to reheat french fries, and you are an idiot for suggesting otherwise. (I am paraphrasing, but this was the feel of the comments, at least as I recall it.)Maybe I should get an air fryer, I thought, before waiting another eight months to get one. (I finally got the Instant Pot Vortex Mini, because it is small and red and $50.)The tiny, powerful convection ovenwhich does not technically fry anythingis quite handy. Ive already integrated it into my everyday cooking rotation, but I started with cold fries (and ate them for breakfast), because thats what brought us to this point in the first place.My friends, you (and everyone else who yelled at me) were not lying. When it comes to restoring limp, cardboard-like fries to their former crisp, golden glory, the air fryer kicks the waffle makers ass (though I maintain waffled leftover fries make excellent breakfast potatoes). That said, not everyone has an air fryer. (Though if you're in the market for one, I suggest these.) You can also use the conventional oven or a frying pan to get your spuds crispy again. Here are the three best ways to reheat french fries.What makes leftover fries so sad?Leftover fries are sad and soggy due to moisture migration, and the air fryer takes care of that nonsense in short order. Once a fry starts to cool, the water inside the fluffy starch granules moves out towards the crust, rendering the insides of the fry grainy and the outsides mushy. How to reheat fries in the air fryerBeyond reheating completely cold fries, this is a great way to revive takeout fries that may have sat in a paper bag or plastic container for too long. Just five to 10 minutes in a 375-degree air fryer perks em right back up. Timing will vary from air fryer to air fryer but, unlike the Instant Pot or a sous-vide circulator, its very easy to check on your air fried food mid-cookjust slide the little basket out. Try not to over-pack the air fryer; you want the hot air to be able to circulate around each fry. It took my air fryer a mere five minutes at 375 to restore cold, lifeless, fairly thick-cut breakfast fries to their former glory, which is dangerously quick, particularly in a household that is prone to over-ordering french fries. While a little overlapping is fine, try not to crowd your fries. Credit: Allie Chanthorn Reinmann Why reheat fries with an air fryer?An air fryer cant rehydrate those starch granules, but it certainly revives a frys soggy outsides. The hot, circulating air drives off moisture and gets any dormant fry grease movin and groovin, re-crisping the potatos crust. And while the insides arent quite as tender and fluffy as they are when you first take them out of a deep fryer, they are pretty damn close. The ones I ate for breakfast this morning were almost indistinguishable from fresh fries, though its worth noting that they seemed to be a fresh-cut, once cooked kind of fry, so this may have only been their second (not third) heating.How to reheat fries in the ovenReheating french fries in the oven is the second best way because you can do big batches and it's a much more hands-off method than the frying pan method below. Credit: Allie Chanthorn Reinmann To reheat fries in the oven, preheat the oven to 400. While that's heating up, arrange a metal wire rack over a sheet pan. Spread out the cold fries over the rack so they're not overlapping. The elevated rack will allow the hot air to circulate underneath and around the fries so you don't have to do any flipping. Bake the fries for 15 to 25 minutes. I suggest checking on them after 15 minutes to assess their crispiness. Depending on how thick or thin they are, it's possible to dry them out if they bake too long. How to reheat fries in a frying panIf you don't have any other choice, or you have only a handful of fries that you're trying to revive, there's the frying pan method. Credit: Allie Chanthorn Reinmann Grab a relatively large frying pan. There should be enough room for the fries to lay flat in a single layer. Unlike in the oven or the air fryer, it's the direct contact with the hot surface that's going to heat up the oil that imbues the crust of each fry. Some other folks recommend adding oil to the pan, but I disagree. This only made my fries oily in a gross way. Heat the fries over medium-low heat. They'll begin to sizzle after two minutes or so. Proceed to rotate them every minute or two so the other sides crisp. After about 10 minutes of flipping the fries, all of the sides should be hot and crispy. This is a great idea if you only have a single serving of fries and you don't mind tending to them the entire time. It's quicker than the oven method, but if you're inconsistent you might end up with scorched spots on some fries.Tips for reheating friesDon't crowd. Lay the french fries in a single layer and try to avoid a lot of overlapping. This will prevent any steam from getting trapped and allow your taters to crisp faster. If you have a lot of fries to reheat, it might be best to do it in batches or just use the oven.Spritz 'em lightly with oil. For a just-out-of-the-fryer sizzle, give your fries a light spritz with a neutral cooking oil. Specifically for the air fryer, a fresh layer of fat conducts the heat that much more effectively.Check on them mid-cook. Cooking time varies depending on the thickness of the french fry you're reheating (steak cut? shoestring? crinkle?), so it's important to check on your spuds once or twice. Especially with the speed of the air fryer, a few minutes too long is the difference between crisp and fluffy or hard and dry.