Begin by washing and peeling the sweet potatoes thoroughly. Pat them dry with a kitchen towel.
Using a mandoline slicer or a sharp knife, cut the sweet potatoes into thin, even slices (about ⅛ inch thick). The thinner the slices, the crispier they'll be!
In a large bowl, combine the sweet potato slices, olive oil, paprika, garlic powder, sea salt, black pepper, and cayenne pepper if using. Toss everything together until the sweet potatoes are evenly coated.
Preheat your air fryer to 375°F (190°C) for about 3-5 minutes. While it preheats, allow the sweet potatoes to sit for a few minutes to absorb the flavors.
Once the air fryer is ready, arrange the sweet potato slices in a single layer in the air fryer basket. Do not overcrowd; you may need to do this in batches.
Air fry the sweet potatoes for 10-12 minutes, shaking the basket halfway through cooking for even crispness. If you prefer them crispier, you can add an additional 2-3 minutes.
Once cooked, remove the sweet potato chips and let them cool on a wire rack. They will continue to crisp up as they cool.