Can you put aluminium foil in an air fryer?

Only if all of these are true

• Your manual must permit it. Check your own manual first. At least one manufacturer prohibits foil in its air fryers outright, and that prohibition governs its appliances whatever the physics allows.
• Must be weighed down by food. Where it is permitted, foil must be weighed down by the food sitting on it. A loose sheet in a drawer machine is the failure mode this material is known for.
• Must not block the airflow. Never line the whole base or cover the cooking surface. The stated reason one manufacturer gives for prohibiting foil is overheating from restricted airflow, not fire.
• Must not reach the heating element. Keep it well clear of the element above. In a drawer machine that clearance is a few centimetres and a lifted sheet closes it instantly.
• Never in an empty or preheating chamber. Never preheat with foil in an empty chamber. With no food to hold it down there is nothing between the sheet and the fan.

What the manufacturers actually say

The manufacturers do not always agree, and silence is not permission. Each row below is what one company’s own manual says — or, where it says nothing, the fact that it says nothing.

• Cosori: Permits it in specific conditions

  The manual states that lining the basket with foil may make cleanup easier, and excludes the crisper plates from that permission — covering their perforations would obstruct the airflow the appliance depends on.

  Cosori Dual Blaze TwinFry 10L Air Fryer CAF-TF101S-AES — User Manual — read for a flex-drawer air fryer (one drawer, removable divider)

• Russell Hobbs: Prohibits it

  For its combination microwave, the manual prohibits metal pans, dishes with metal handles and anything with a metal trim, along with paper-covered wire twist-ties.

  Russell Hobbs 4-in-1 25L Digital Combination Microwave with Air Fryer Function RHM2564 — Instructions — read for a combination microwave with air fry

• Instant: Prohibits it

  Do not cover the cooking tray or any part of the oven with foil. The manual gives the reason: it will cause the appliance to overheat.

  Instant Vortex Plus VersaZone 8.5L Air Fryer — User Manual — read for a flex-drawer air fryer (one drawer, removable divider)

• Instant: Prohibits it

  The same prohibition appears in a second manual from this manufacturer, for a dual-basket machine, in the Air Frying Cautions.

  Instant Vortex Plus Dual Air Fryer 7.6L — User Manual — read for a dual-basket air fryer

• Breville: Permits it

  A manufacturer recipe in the manual instructs the cook to line one of the air flow racks with foil and place the vegetables on it.

  Breville Halo Rotisserie Air Fryer Oven VDF127 — Instruction Manual — read for a oven-style air fryer

• Ninja: Says nothing about it

  The manual contains no instruction of any kind about foil. It does note that the fan will lift lightweight items and advises securing them, which is related and is not permission.

  Ninja Foodi MAX Dual Zone Air Fryer AF400UK — Instructions — read for a dual-basket air fryer

What can go wrong

Foil is the question this whole section exists for. It is genuinely useful — it catches drips, it shields the tips of a rack of lamb, it stops marinade welding food to the plate — and it is light enough to be picked up by the fan and driven into a glowing element. Neither of those facts cancels the other, and the manufacturers who have written about it do not agree.

• Can be lifted by the fan

  Weigh it down with the food itself, cut it smaller than the basket floor, and never put it in an empty chamber.

• Can block airflow

  Leave the perforations and the chamber's air path clear. Use a piece smaller than the base rather than a liner that covers it.

• Sits close to the heating element

  In a drawer machine, keep the food and anything on it well below the element. In an oven-style machine on a lower rack the clearance is much greater and the risk correspondingly lower.

Temperature limit

Around 260°C.

Aluminium's melting point is far above any air fryer's range, so temperature is not the constraint. The limit recorded here is the top of the appliance class's own range and exists so the page does not imply a thermal risk that is not the real one — the risks are airflow and lift.

It depends on your appliance

The answer is not the same in every machine. Where the element sits relative to the food, and how hard the fan blows, change what this material does.

• Basket air fryer — Safe only in specific conditions

  The element sits a few centimetres above the basket and the fan is directly above that. Loose foil has the shortest possible distance to travel and the strongest airflow acting on it. Weighted under food it is a manageable risk; loose it is the worst case in this appliance class.

• Dual-basket air fryer — Safe only in specific conditions

  As for a single basket, in each drawer. One manufacturer of this architecture prohibits foil in its machines entirely, so the manual matters more here than the physics.

• Flex-drawer air fryer (one drawer, removable divider) — Best avoided

  The manufacturer of the flex-drawer machine in this catalogue prohibits covering the cooking tray or any part of the appliance with foil, stating it will cause the appliance to overheat. That is a direct instruction about this architecture from the company that built it.

• Oven-style air fryer — Safe only in specific conditions

  An oven-style cavity has a shelf's worth of clearance to the element and a manufacturer of this architecture prints a recipe instructing the cook to line a rack with foil. The same material, the same physics, and a materially lower risk because of the geometry.

• Combination microwave with air fry — Unsafe

  In a combination microwave the risk is arcing rather than lifting, and it is categorical. Two manufacturers of this architecture prohibit metal in microwave and combination modes: one documents blue sparks and crackling as a fault caused by an unsuitable metal container, the other prohibits metal pans, handles, trim and wire twist-ties. Where foil is permitted at all it is on an enamel tray in convection-only mode.

• Countertop oven with air fry — Safe only in specific conditions

  As for oven-style: more clearance, lower air velocity at the food, and correspondingly less chance of a weighted sheet being lifted. The manual still governs.

Your manual governs

Food contact

Aluminium is used in direct food contact throughout the food industry. Prolonged contact between foil and strongly acidic or salty food can cause pitting and some transfer of aluminium; for a short cook this is not a concern most authorities address.

Evidence and confidence

Things made of this, and whether they are worth owning

• Silicone basket insert — Works, but costs you results — The most-sold air fryer accessory and the commonest way to make an air fryer cook worse. It works; it costs you the thing you bought the machine for.
• Multi-level rack — Useful for a specific job — It adds a level. It does not add capacity, and one manufacturer states plainly that only one level may be used in air-fry mode.

Use this instead

• Baking parchment — Two manufacturers now prohibit it outright and one gives the mechanism. Sprint 2 recorded every manufacturer as silent; that is no longer true, and the verdict has hardened.
• Silicone liners and moulds — Heavy enough not to be lifted, and rated above the temperatures these appliances reach. The airflow question is the one that remains.
• Metal tins, trays and cookware — Explicitly permitted by one manufacturer for baking, and recommended by three others whenever a batter is involved.