Wash and dry the asparagus. Trim off the woody ends of the asparagus.
If required per your air fryer model, preheat to 400 degrees F.
Toss the trimmed asparagus with oil and salt.
Spread out the seasoned asparagus in a thin layer in the air fryer. It is okay if some spears overlap each other a tiny bit, but you don’t want significant overlap.
Place the basket or tray into the air fryer and set to air fry at 400 degrees F for 4 minutes.
Remove the basket or tray and give the asparagus a shake. Return to the air fryer and continue to air fry at 400 degrees F for 3 minutes.
If the asparagus has not reached the level of doneness/crispiness you prefer, continue to cook in 1-minute intervals at 400 degrees F.
Season with additional salt if needed and serve immediately.
Storage: Allow the asparagus to cool slightly and place in an airtight container. Store in the refrigerator for up to 4 days.Reheating: To reheat the asparagus, place it into the air fryer for 3-4 minutes, at 380 degrees F.If using a smaller air fryer: You may need to work in batches to allow the asparagus to be evenly spaced. Keep the first batch in the oven at 200 degrees F while the other batch cooks up.