Cut the potatoes into thin sticks about 1/4-inch in thickness.
Preheat a 2.5-liter air fryer to 400 degrees F.
Place the potatoes in a large mixing bowl. Pour in the oil and sprinkle with the garlic powder, paprika, chili powder and 1 teaspoon salt. Toss until evenly coated.
Lay the potatoes in a single layer into the basket of the air fryer. Cook, tossing every 5 minutes, until crispy and browned along the edges, 15 to 20 minutes. (For best results, don't overfill the basket.)
Remove the potatoes from the air fryer and place on a serving platter.
For extra-crispy fries, soak the sliced potatoes in cold water for at least 1 hour before cooking. When ready, drain, rinse and pat dry before coating the potatoes in the oil and spices.