When I first started researching air fryers, it sounded very similar to a convection oven (which I already have). It turns out both appliances make food crispy and speed up cooking times by using a fan to circulate the air around the food. Convection ovens are much larger so they can hold a lot more food. Air fryers are small, so the capacity is limited. However, because of its size, the air fryer may cook slightly faster. They are both very similar and it all depends on what your needs are.