What can you put in an air fryer? The container rules, by material

“If it is oven-safe it is air-fryer-safe” is the line you will read almost everywhere, and it is right about three materials out of five. The trouble is that an air fryer is not a small oven in the way that sentence implies. A conventional oven surrounds food with heated air from elements several inches away. An air fryer sits a high-wattage element a few inches above the food and drives air across it hard. That is a harsher environment for a container than an oven at the same dial setting, and the material that minds most is the one in every kitchen cupboard.

The two rules underneath every answer

Before the materials, there are two constraints that apply to anything you put in the basket, and most of the bad outcomes come from breaking one of them rather than from the material itself.

Clearance. Nothing may touch or nearly touch the element. Manufacturers publish a minimum gap and it is usually an inch or more of free air above the food. A dish that raises the food closer to the element turns a safe cook into a scorched one, and in the case of anything light it is a fire risk. The same logic governs where the machine itself sits, which we work through in air fryer clearance and placement.

Airflow. The perforated floor of the basket is not decorative. It is the return path for the air the fan is circulating. Put a solid-bottomed dish on it and you have converted the machine into a small radiant oven — food will cook, but it will not crisp, which is the whole reason you bought the thing. If your results have gone flat, this is one of the usual suspects in air fryer not crisping.

Metal: yes, and it is the default

Oven-safe metal is the material an air fryer was designed around. Stainless steel racks, cake tins, small sheet pans, foil trays, springform bases and skewers are all fine, and metal has the advantage of heating quickly and taking the thermal swing without complaint. The practical limits are size and height rather than safety: a tin that fills the basket wall to wall blocks the air from coming back down the sides, and a deep tin lifts the food into the element.

The one metal accessory that genuinely earns its place is a stainless rack, because it does the opposite of a solid dish — it adds a second layer of food while leaving the airflow intact. We rank the ones worth owning in air fryer accessories.

Glass: read this one carefully

This is the question people actually search for, and the honest answer is not the reassuring one. Pyrex publishes explicit usage guidance for its glass bakeware, and it draws a line between an oven and everything else:

“Pyrex glass cannot be used in an Air Fryer as this is a direct heat source.”

The same instruction bars Pyrex glassware from the stovetop, the broiler, a barbecue grill and a toaster oven, all for the same reason. It also tells you to preheat the oven completely before the dish goes in, because the exposed element during preheat is itself a direct heat source. An air fryer is that exposed element, permanently, a few inches from the dish.

The mechanism is thermal shock. Glass fails when one part of it expands faster than the part next to it, and the two fastest ways to arrange that are a hot radiant element close to one face, and a cold dish meeting hot air. Taking a Pyrex dish out of the fridge and sliding it into a preheated air fryer manages both at once. Whether a particular dish survives that is a question about its history of small chips and scratches, which is not a question you want the answer to at 450°F.

None of this makes glass a bad material for cooking. It is the material we rank first on the coating question, precisely because it cannot shed anything into your food — the case for it is in glass vs metal air fryer baskets. The point is narrower than that: household glass bakeware is not rated for this appliance by the people who made it.

The exception: glass made for the machine

Glass containers sold as part of an air fryer are a different proposition, because the manufacturer has rated the vessel and the heat source together. The Ninja Crispi is built entirely on that idea — borosilicate containers that go from the fridge to the heating unit and back, with no coated basket anywhere in the system. If glass is what you want, this is how to get it without arguing with a bakeware manufacturer's instructions.

Ceramic and stoneware: usually yes, with the cold-start caveat

Oven-safe ceramic ramekins, small stoneware dishes and the ceramic inserts sold for air fryers generally cope, and they are the sensible choice for eggs, dips, small bakes and anything that would otherwise run through the perforations. The caveats are the familiar ones for any fired ceramic: it does not like going from cold to hot quickly, a crazed or hairline-cracked glaze is a failure waiting to happen, and decorative pieces are not always rated for oven use at all. If the base carries no oven-safe mark, treat it as decorative.

Silicone: safe, but understand what it does

Food-grade silicone tolerates the temperatures easily and is the most forgiving material for anything wet or sticky. Its drawback is not safety, it is physics: a solid silicone pot seals the perforated base completely, so you are steaming and baking rather than air frying. Use it deliberately — for a saucy dish you could not otherwise attempt — rather than as a permanent basket lining. We cover the reusable ones, and where they genuinely beat paper, in air fryer accessories.

Paper: yes, with the rule everyone skips

Parchment liners are fine and they are the tidiest solution for sticky cooks. Reynolds, which makes the most widely sold ones, publishes three conditions and they are not optional: the liners are heat-safe to 400°F on the air fryer setting, they go in afterpreheating rather than before, and food must sit on top to hold them down. Their warning is explicit — a bare liner “can be lifted by the circulating air and come into contact with the heating element, which is a fire hazard.” The full set of rules for paper and foil, including the acidic-food problem foil has and parchment does not, is in can you put foil in an air fryer.

Never: the short list

Plastic of any kind, including the lids and tubs marked microwave-safe — microwave-safe is a statement about a completely different heating mechanism and carries no oven rating. Styrofoam and takeout containers. Melamine. Paper plates, kitchen roll and napkins, which are light enough to lift into the element. Anything with a plastic handle, knob or seal. Cardboard, including the tray a supermarket pizza arrives on.

The whole thing as a table

One last habit worth having

Whatever goes in, take it out with something that will not gouge the surface underneath. Metal tongs dragged across a coated basket are the single most common cause of a basket that starts shedding a year later, which is a different failure from anything on this page but a far more likely one. That argument, with the evidence, is in why air fryer baskets peel.