Updated 10 August 2026 · Written by Daniel Wright
An air fryer works by circulating very hot air rapidly around the food using a powerful fan, which crisps and browns the surface much like deep frying but with little or no oil. It is essentially a compact, high-powered convection oven, cooking food quickly and evenly from all sides.
An air fryer rapidly circulates hot air around food with a fan, crisping it with little or no oil. It is a compact convection oven.
The Science in Simple Terms
Inside an air fryer, a heating element warms the air and a strong fan whips it around the food at high speed. This fast-moving hot air cooks the surface quickly, triggering the browning reaction that gives fried foods their crispy, golden exterior, but without submerging anything in oil.
Why It Crisps Without Oil
Because the hot air reaches every side of the food at once, moisture on the surface evaporates fast and the outside crisps up. A light coating of oil helps some foods brown further, but naturally fatty foods need none. This is why an air fryer gives fry-like results with a fraction of the oil, as compared in air fryer vs deep fryer. For the full range of models, see the best air fryers.
Frequently Asked Questions
Is an air fryer just a small convection oven?
Essentially, yes. Both use a fan to circulate hot air, but an air fryer is more compact with a stronger, more concentrated airflow, which crisps small batches faster.
Does an air fryer use radiation like a microwave?
No. An air fryer uses a heating element and a fan to move hot air, cooking by convection. A microwave uses microwaves to heat the water in food, which is a completely different method.
