Gather all ingredients.
Cut each potato lengthwise into ⅜-inch-thick slices; cut slices into ⅜-inch-wide sticks. Place potato sticks in a bowl of cold water; soak to release excess starches, about 5 minutes. Drain.
Pour boiling water over potatoes until covered by a few inches; set aside for 10 minutes. Drain potatoes; transfer to some paper towels. Blot excess water from potatoes; cool completely, at least 10 minutes.
Place cooled potatoes in a bowl; drizzle with oil. Season with cayenne; toss to coat.
Preheat an air fryer to 375 degrees F (190 degrees C) according to manufacturer's instructions.
Stack potatoes in a double layer in the air fryer basket.
Air fry for 15 minutes. Slide basket out; toss fries. Continue air frying until golden brown, about 10 minutes more. Transfer fries to a bowl; toss with salt. Serve immediately.
