Arrange the frozen onion rings in a single layer inside the air fryer basket. There’s no need to apply any oil spray.

Set the air fryer to 400°F and cook for 8 minutes. Halfway through, give the basket a shake or gently stir the rings to ensure even cooking. If you're preparing a larger amount or notice uneven cooking, try flipping the rings more frequently in subsequent batches.

For extra crispiness, continue cooking at 400°F for an additional 2-4 minutes, adjusting to your preferred level of doneness. Add salt and pepper to taste before serving, if desired.