Start by preheating your air fryer to 350°F (175°C) for a few minutes. Preheating ensures even reheating of the bagel.

If the bagel is sliced, it's recommended to keep the halves together to prevent the cut side from becoming overly toasted. If it's unsliced, you can either reheat it whole or slice it first depending on your preference.

Once the air fryer is heated, place the bagel(s) in the fryer basket in a single layer, ensuring they aren't overlapping or touching.

Heat the bagel for about 3-4 minutes. If you've sliced it, you may want to check it at the 2-minute mark to ensure the cut sides aren't getting overly crispy. The exact time can vary based on your specific air fryer model and the size and thickness of the bagel, so you might need to adjust the timing accordingly.

Once done, carefully remove the bagel from the air fryer (it will be hot) and let it sit for a minute. Enjoy it warm with your favorite toppings!