Use bone-in, skin-on thighs. Pat completely dry with paper towels — this is critical for crispy skin. Coat lightly with oil, then season all sides with salt, garlic powder, onion powder, smoked paprika, and black pepper. Press seasoning to adhere evenly; keep the layer thin. Preheat air fryer to 400°F before adding chicken.

Place thighs skin side up in a single layer in the preheated 400°F air fryer basket — no stacking or crowding. Work in batches if needed; a standard 5-qt basket fits about four thighs. Cook at 400°F: 10 min skin side up → flip, 8 min skin side down → flip again, 2 min skin side up. Total time: 18–24 min depending on thigh size and air fryer model. Alternatively, skip the flips and cook skin side up the full 18–24 min, checking at 18 min. Done when a thermometer inserted into the thickest part (not touching bone) reads 175°F. 165°F is the USDA minimum, but 175°F gives the best texture for thighs. Not there yet? Keep cooking in 1–2 min increments.

Chicken thighs are done at 175°F internal temp at the thickest part away from the bone. Juices should run clear and skin should be deep golden and crisp. Always use a thermometer — don't rely on color alone. Rest 3–5 minutes before serving so juices redistribute. Serve hot for maximum crispiness. If skin isn't crispy, add 1–2 minutes skin side up at the end. Leftovers keep 3–4 days refrigerated; reheat in the air fryer.