Most air fryers are a black plastic drawer you can’t see into. The Ninja CRISPi isn’t. It’s a heating pod that sits on top of a glass dish, so you can watch your chips go golden, then lift the pod off, put a lid on the dish and stick the leftovers in the fridge. For a small UK kitchen, where every appliance has to earn its spot on the worktop, that’s a clever idea. It isn’t flawless, though, and nearly all the complaints about it are about one specific part.

At a glance

  • Best for: one to three people in a flat, student house or small kitchen who batch cook and hate washing up
  • Standout feature: the glass containers double as serving dishes and fridge storage, so food goes from cooking to leftovers without changing bowls
  • Watch out for: the crisper plates, which are the weak point in owner reviews
  • Skip if: you regularly cook for a big family, or you want lots of presets and a big digital screen

How it works

The CRISPi comes in two parts. The top half is the “power pod”, a 1700W unit with the fan, heating element and controls. The bottom half is whichever glass container you’re cooking in. You get two: a 3.8 litre one and a 1.4 litre one, each with a non-stick crisper plate that sits inside and a storage lid for afterwards.

There are four functions: Air Fry, Roast, Keep Warm and Recrisp. That’s a short list next to some of Ninja’s bigger machines, but those four cover what most people use an air fryer for. Ninja says the large dish takes a whole 1.2kg chicken with veg and makes up to 6 portions, which is optimistic if those portions are hungry adults. The small one is for sides, a single portion, or reheating last night’s roast potatoes.

The glass is described as thermal-shock resistant, and both containers are dishwasher safe. Ninja markets the glass as a way to cook without PFAS. Bear in mind that the crisper plates are still non-stick coated, so the food sits on a coated plate, not straight on the glass.

With the large dish in place it measures 34.5cm high, 30.4cm wide and 34cm deep. It’s not tiny. There’s no drawer to pull out, but you lift the pod straight up to get at the food, so it needs headroom under low wall cupboards. You’ll also need a heatproof spot next to it to put the hot pod down.

The good bits

  • Cleaning is easy. UK owners mention this more than anything else. The glass dish rinses out or goes in the dishwasher, and there’s no basket mechanism with corners where grease builds up.
  • You can see the food. Being able to see how brown things are without stopping the cook is handier than it sounds, especially with stuff that goes from done to burnt quickly, like halloumi or reheated pizza.
  • Fewer dishes. Cook in it, serve from it, put the lid on and put it in the fridge. If you batch cook on a Sunday, that saves real washing up.
  • Two sizes to swap between. Using the small dish for one person means you’re not heating a big empty space for a handful of chips.
  • Owners say it crisps well. Chicken wings are the food people mention most, and the general verdict is even, consistent cooking. Plenty of owners say it’s replaced the oven for everyday meals.

The not-so-good bits

  • The crisper plates. This is the big one. Several owners say the rubber feet on the large crisper plate tore or broke early, in one case before it was even used. Another says the replacement plate still sat lopsided, so food rolled to one side as it cooked. Replacement plates are now sold separately, which says something. The small plate gets far fewer complaints.
  • Crumbs get trapped. One detailed review points out a small gap between the base of the glass dish and its feet, where bits of food collect and are awkward to get out. It doesn’t affect cooking, but if you’re fussy about cleaning, you’ll notice it.
  • It gets hot and blows warm air out. The glass and the pod are hot when it’s running, and you’ll burn your fingers if you try to straighten a plate mid-cook. That same owner reports that the warm air coming out the back melted a plastic bottle sitting behind it. That’s one person’s experience, but it’s an easy one to avoid. Leave proper clearance around it, especially under wall cupboards.
  • Not every review is a fan. A handful of 1-star reviews say food cooked unevenly or came out undercooked. Most owners report the opposite, so it may be a faulty unit or overloading, but check the middle of anything chunky before you eat it.
  • Simple controls. Four functions is fine for most people, but there’s no dehydrate, bake or preset programmes. If you want lots of options, look elsewhere.

Who should buy it

The CRISPi makes the most sense for people who cook small batches and want less to wash up: a couple in a flat, a student, or someone living alone who keeps the oven off on weeknights this winter. The glass-dish-as-storage idea is the thing you’re really paying for. If you’d use it, this is better than a basket fryer for you. If you wouldn’t, a cheaper basket model does the same cooking.

If you just want the smallest decent air fryer for one, have a look at the COSORI 2L or our round-up of the best air fryers for one person. If you want a conventional basket with a bit more room, the Tower Vortx 4.2L is a good comparison, and the Ninja Double Stack XL is the one to look at if you’re feeding a family.

Getting the best out of it

  • Use the small dish whenever the food fits. It’s the better match for one person, and owners have fewer complaints about the small plate.
  • Check the large crisper plate is sitting level before you load it. If it tilts, sort it out while it’s cold, not halfway through cooking.
  • Don’t fill the dish to the top. Air needs to move round the food to crisp it, so spread chips or wings out and give them a shake halfway.
  • Use Recrisp for leftovers. It brings chips, pizza and roast potatoes back much better than a microwave does.
  • Like most new air fryers, it can smell a bit for the first few uses. If yours does, our guide on why air fryers smell like plastic covers what’s normal and what isn’t.

Cleaning and safety

Let everything cool before you lift the pod off or wash the glass. Thermal-shock resistant doesn’t mean you should run a hot dish under the cold tap. The glass containers and crisper plates are dishwasher safe. Wipe the pod with a damp cloth only and never get it wet. Every so often, poke a skewer wrapped in kitchen paper into the gap under the dish to get the crumbs out. To keep the non-stick on the plates in good shape, skip metal utensils and scourers (see our tips on cleaning an air fryer without scratching it). Keep it away from anything plastic or heat-sensitive while it’s running.

FAQ

Can you put the CRISPi glass dishes in the fridge or freezer?
The containers come with storage lids for keeping leftovers in the fridge, which is the whole idea. Let the glass cool to room temperature first, and check Ninja’s manual before putting it in the freezer or moving it straight from the freezer to the pod.

Is the Ninja CRISPi big enough for a family?
Ninja says the 3.8L dish makes up to 6 portions and fits a 1.2kg chicken. In practice it suits one to three people best. A bigger family that wants a main and sides at the same time will be better off with a dual-drawer model.

Is the CRISPi completely non-stick free?
No. The glass containers have no coating, but the crisper plates the food sits on are non-stick. If avoiding coatings is your main reason for buying it, that’s worth knowing.

Is it cheaper to run than an oven?
For small portions, generally yes, because it’s heating a much smaller space for less time, and plenty of owners say the same. Our breakdown of what an air fryer really costs to run goes through the maths.

Can I buy a replacement crisper plate?
Yes. Replacement plates are now sold separately, which is handy given that the large plate is the part owners complain about most.

The verdict

The Ninja CRISPi is one of the more original air fryers around. Cooking, serving and storing in the same glass dish suits small kitchens and batch cooks well, and owners rate how easy it is to clean and how evenly it crisps. The large crisper plate is a real weak spot, and you’ll need to give it space to breathe on the worktop. If you can live with those, it’s a smart winter buy that’ll keep the oven off most nights.

Ninja CRISPi 3.8L 4-in-1 Glass Air Fryer (FN101UKGY) on Amazon UK