Preheat the air fryer: Set it to 390°F (200°C) for 3 to 5 minutes. A hot basket helps the fish cook evenly and release cleanly.

Pat the fish dry: Use paper towels to remove surface moisture. This helps the seasoning stick and prevents steaming.

Season the fillets: In a small bowl, mix olive oil, lemon zest, lemon juice, black pepper, salt, garlic powder, and onion powder. Brush or spoon the mixture over both sides of each fillet.

Prep the basket: Lightly spray the air fryer basket with nonstick spray to reduce sticking. You can also use a perforated parchment liner made for air fryers.

Arrange the fish: Place fillets in a single layer, not touching. Work in batches if needed. Do not overcrowd or the fish will steam instead of crisping at the edges.

Air fry: Cook at 390°F (200°C) for 7 to 10 minutes, depending on thickness. Thin tilapia may be done at 6 to 7 minutes; thicker cod or halibut can take 9 to 11 minutes.

Check for doneness: The fish should flake easily with a fork and reach an internal temperature of 145°F (63°C). If needed, cook 1 to 2 minutes longer.

Finish and serve: Transfer carefully with a thin spatula. Garnish with fresh parsley or dill and extra lemon wedges. Serve with rice, quinoa, or a crisp salad.