There is no universal yes-or-no answer for every air fryer. Some manufacturers allow aluminum foil under specific conditions, while others advise against it on certain models. Your appliance manual is the first authority.
Why foil can create problems
An air fryer cooks by moving very hot air at high speed. Foil that covers perforations or too much of the basket can restrict airflow and reduce cooking performance. A loose sheet can also be lifted toward the heating element.
Manufacturers do not all give the same rule
Philips advises against foil on several models because it can disrupt airflow and potentially be drawn into the heater if unsecured. COSORI allows foil in some units as long as airflow is not blocked, the foil is held down by food, and it stays away from heating elements. That difference is why model-specific instructions matter.
If your manual allows it
Use only the amount you need, keep ventilation areas open, and place food on top so the foil cannot move. Do not line the entire basket just to simplify cleanup, and do not preheat with an unsecured sheet.
Do not cover the parts designed to move air
Basket perforations and air inlets and outlets are part of the cooking system. Blocking them changes airflow, temperature, and cooking time. An air fryer is not simply a small conventional oven tray.
Be cautious with highly acidic foods
Tomato, citrus, and strongly acidic marinades can react with aluminum and affect flavor or the foil surface. A manufacturer-approved oven-safe dish may be a better choice when you need to contain liquids.
If the manual says no, the answer is no
It is not worth improvising just to save cleanup time. Model-specific baskets, liners, and accessories are safer choices when approved.
The useful rule is: manual first; if foil is permitted, use a small secured amount and never block airflow.
Sources
- Philips Support — Can I use baking paper/tin foil in my Philips Airfryer? — Some Philips models advise against foil because of airflow and heating-element risks.
- COSORI — 9.0-Qt Dual Basket Air Fryer FAQ — Allows foil with conditions: preserve airflow, secure it with food, and keep it away from heaters.