Look first at the cooking capacity and basket shape; a square basket (like Cosori) often provides more usable space than a round one. Next, compare power (wattage) and maximum temperature, since higher wattage and up to 450 °F (as seen in several models) deliver faster, crispier results. Finally, consider the variety of preset functions, ease of cleaning (nonstick or dishwasher‑safe baskets), and the appliance’s footprint for your kitchen.

Cosori’s TurboBlaze technology uses a 3600 rpm fan and five fan speeds, offering precise 90°–450 °F control, while Ninja relies on Max Crisp technology with a single high‑heat setting up to 450 °F. Ninja provides a slightly larger 6.5‑qt basket that can hold up to 9 lb of wings, whereas Cosori’s 6‑qt square basket is more compact but still spacious for family meals. Both include multiple cooking functions, but Cosori adds a dehydration and proofing mode, giving it a broader versatility edge.

Ceramic coatings, featured on Cosori and Bella models, are free of PFAS, PFOA, and other harmful chemicals, making them a healthier choice for low‑oil cooking. They also tend to be more scratch‑resistant and easier to clean than traditional Teflon surfaces, which can extend the appliance’s lifespan. If you value easy cleanup and a non‑toxic cooking surface, the modest price premium is often justified.

The Cosori 9‑in‑1 TurboBlaze leads with nine functions—including air fry, roast, bake, broil, dehydrate, frozen, proof, reheat, and keep warm—plus five dedicated presets. Ninja follows with six functions and a strong Max Crisp setting, while Instant Pot Vortex models provide four to six functions but lack the dehydration and proof options. For the widest range of cooking methods, Cosori is the most versatile choice.

Higher wattage (e.g., 1800 W in the Cuisinart or 1750 W in Bella) heats the air faster, reducing cook times and improving crispness. A broader temperature range, especially a max of 450 °F, allows you to sear and dehydrate foods that lower‑temp models (max 400 °F) cannot handle as efficiently. Together, these specs determine how quickly and evenly food cooks.

Bella’s slim 6‑qt air fryer is marketed for tight countertops, offering a narrower profile while still holding up to 5 lb of food. Chefman also emphasizes a compact footprint with a sleek, narrow chassis that fits easily on small kitchens. Both provide good capacity without sacrificing counter space, making them ideal for apartments or limited kitchens.

Presets eliminate guesswork by automatically setting time, temperature, and fan speed for popular foods like fries, wings, or vegetables, ensuring consistent results. Models such as the Cosori, Bella, and Instant Pot Vortex include multiple one‑touch presets, which speed up meal preparation and are especially helpful for beginners. They also reduce the need to monitor cooking stages, freeing you to multitask.

Start by listing the functions you’ll actually use; if you need only air fry and reheat, a basic model like Chefman may offer the best value. If you want advanced features such as dehydration, proofing, or a large library of app recipes, investing in a higher‑priced unit like Cosori or Ninja can pay off in versatility. Consider long‑term durability, warranty, and ease of cleaning, as these factors influence total ownership cost beyond the sticker price.