The air fryers needed just 5 minutes to preheat, while our deep fryer took 15 minutes to get the oil hot. But the deep fryer cooks faster. All in all, when you factor in the time needed to preheat, the air fryers are slightly faster.

Time to eat. We gathered staffers in the lab to try common foods that are recommended in the owner's manuals—French fries, chicken wings, and chicken nuggets. We cooked batches of the same foods in many of the air fryers and, for comparison, a deep fryer. 

Staffers were not told which cooking method was used for each food, yet everybody could tell which foods were deep-fried. While none of the air fryers duplicated deep-fried results, they all turned out nicely cooked food.  

The air fryer ratings provide a summary of each model, offering you a good look at each. But before you shop, consider the following.

• Prices vary widely. The air fryers is our tests cost from $60 to $250, and we've seen models for as much as $300. 

• Capacities vary too. Air fryers are designed to neatly fit on your counter, and most aren't big enough to cook for a crowd, unless you cook in batches. The models we tested have capacities between 2 and 5.8 quarts. When cooking, do not overcrowd the basket. This can block the hot air from reaching all the food. The result? Some food is cooked more than others.

• Warranties differ. The shortest warranty of the air fryers we tested is 60 days—not exactly a confidence booster. Others in the air fryer ratings have a one or two-year warranty.