What Is an Air Fryer and How Does It Work?

Written by Stephanie Watson, Marijke Vroomen Durning, RN
Medically Reviewed by Zilpah Sheikh, MD on November 16, 2025
7 min read

Dig into a serving of french fries or a plate of fried chicken, and the pleasure hits you right away — that familiar, crispy crunch and moist, chewy center.

But the appealing taste of fried foods comes at a cost. Research links the oils used for cooking them to health problems such as heart disease, type 2 diabetes, and cancer.

Enter air fryers — appliances that promise the taste, texture, and golden-brown color of oil-fried foods without all the fat and calories. But do these deep fryer replacements deliver on their promise?

Air fryers are devices kept on your countertop. You put the food you want to fry (such as chopped potatoes, chicken nuggets, and zucchini slices) into a slide-out basket in the device. If you want, you can toss them in a light coating of oil.

Inside the device, a fan pushes heated air (up to 400 F) around the food. It’s a bit like a convection oven.

The circulating air cooks the outside of foods first, which creates a crispy brown coating, and keeps the inside soft, just like deep-fried foods. As the food cooks, a container below the basket catches any grease that drops.

Bottom line: Air fryers create the crispy, chewy foods people love — without all the oil.

An air fryer can cook pretty much anything that you would normally fry in oil, such as:

Some models also have toast and bake settings, making them more like conventional ovens. You can use these to bake brownies or roast a chicken. One downside of many of these devices is their small basket size, which leaves little room to cook an entire family meal.

“Air fryers come up in conversation all the time,” says Megan Wroe, MS, RD, CNE, CLEC, wellness manager and registered dietitian at Wellness Center at Providence St. Jude Medical Center. “People seem to be more interested in the convenience aspect of it first, with potential health benefits as a nice side effect.”

By most measures, air frying is healthier than frying in oil. It can cut calories by up to 80% because the food doesn’t absorb the fat as it does in traditional frying.

This cooking method might also cut down on some of the other harmful effects of oil frying. The reaction that happens when you fry potatoes or other starchy foods makes the chemical acrylamide, which research links to a greater chance of getting cancer. One study shows that air frying lowers the amount of acrylamide in fried potatoes by 90%.

Wroe tells her patients that cooking with air fryers can be healthy, but just because something is cooked that way, it isn’t necessarily healthy. “I remind clients that specialty recipes like air-fried Oreos are still not a healthy choice, even if they are technically healthier than a deep fried Oreo from the fair. Overall, I tell clients that an air fryer can be an excellent tool in a healthy kitchen if there is space for it and alongside other cooking methods like steaming, simmering, and raw.”

Is air-fried food as tasty as the classic style? At the end of the day, it’s subjective.

When you fry food, the batter absorbs the oil you used for cooking it. That gives fried foods their satisfying crunch on the outside while keeping the inside moist. Frying also gives foods a rich, dark color that is pleasing to the eye.

You still get a crunch with air frying, but it doesn’t create the exact look or mouth feel as oil frying. One study that compared oil frying with air frying found the two methods led to foods with a similar color and moisture content but different textures and sensory qualities.

Your cooking technique matters, too. If you crowd the small basket too much, your food may cook unevenly, giving you some crunchy and some soggy spots.

Convection ovens work by blowing hot air throughout the oven so the heat is evenly spread throughout. Many ovens now have an option for convection baking or roasting, or you can buy a convection oven alone. Air fryers do pretty much the same thing as a convection oven but are much smaller. So, if you want to cook large amounts of food with the same hot air enveloping the food, you’ll need a convection oven because it has more space.

Air fryers vs. ovens

Ovens without a convection setting use two heating areas called elements, usually at the top and bottom of the oven. The heat doesn’t circulate, but the whole oven heats up to a preset temperature.

Air fryers vs. toaster ovens

A toaster oven is basically a mini-oven, although you can get some toaster ovens that also have a convection setting. The toaster oven bakes and roasts like a typical oven. Many people like to use it for small meals so the kitchen doesn’t heat up as much as it would with their bigger oven.

Air frying vs. microwaving

Microwave ovens cook food differently from conventional ovens, convection ovens, and air fryers. Rather than surrounding the food with heat, microwave ovens use energy to move the molecules in the food, causing heat. Food doesn’t get crispy in a microwave, while that’s one of the air fryer’s major attractions.

Air frying vs. deep frying

People usually buy air fryers so they can have fried foods without the worry of the oil used in a deep fryer. Although you do need to use a little bit of oil in many air fryer recipes, it’s only a little bit compared to the cups of oil you would put in a deep fryer.

Air fryers themselves aren’t dangerous, but like any other form of cooking, they can cause injuries if you’re not careful.

Air fryers get hot — very hot. They can reach almost 500 F, so it’s important to be careful while handling them and when moving the food in the basket or removing it. The parts that seem to cause the most burns are the outside of the food basket and the vent at the back of the machine. It can take a long time for these spots to cool down, so be careful even after you’re finished cooking.

Do air fryers have any health risks?

Air fryers are good tools, but they can have drawbacks. “Air fryers still cook foods at high temperatures and most of them do so in plastic,” Wroe says. “Both these factors have health complications, such as minimized fiber content and plastic toxin consumption.” But she points out that some brands are coming up with other materials in the lining that are better so there will be fewer plastic toxins.

The high heat also increases the risk of advanced glycation end (AGE) products in the foods and degrades nutrients, Wroe explains. But it’s no different from what happens when cooking with high heat in other ways, such as your oven.

In one study, air frying of fish raised the amount of a substance called cholesterol oxidation products (COPs). COPs form when the cholesterol in meat or fish breaks down during cooking. Studies connect these substances to coronary heart disease, hardening of the arteries, cancer, and other diseases.

One way to lower the amount of COPs when you air fry fish, the study shows, is to add fresh parsley, chives, or a mixture of the two. Research shows these herbs act as antioxidants to reduce the COPs in air-fried foods.

Air frying also appears to curb the omega-3 fatty acids in fish. These “good fats” help lower blood pressure and raise HDL cholesterol (good cholesterol) levels, and they may help protect the heart.

An air fryer is a kitchen tool that allows you to prepare foods with crispy, “fried” food results. While it is a healthier way of cooking things compared to a deep fryer, the kind of food you cook is what makes the difference. A high-fat food isn’t going to be any healthier cooked in an air fryer than any other way. Air frying does have a few drawbacks, such as the possibility of some plastic toxins leaching into the food, depending on the materials used to make it. So, while air fryers are safe to use, don’t use them exclusively.

Is it safe to use an air fryer every day?

According to Wroe, while it’s safe to use air fryers, don’t use them exclusively. Maybe use yours to make a fried chicken tender, but then have that with steamed broccoli, for example.

Can air fryers cause cancer?

Air fryers themselves don’t cause cancer. Air frying certain types of food, especially those high in carbohydrates (for example, french fries and chips), causes the formation of a chemical called acrylamide, which is linked to some types of cancer after high exposure. But air frying may actually lower the amount of the chemical compared with traditional frying.

Does air frying destroy nutrients?

Air frying seems to preserve, or keep, most nutrients in food, but there might be some nutrient loss.