The Ninja Double Stack SL300UK is a dual-basket air fryer with a smart vertical design, aimed at households that want the speed and health benefits of air frying without sacrificing half the worktop. With two stacked drawers and a powerful heating system, it promises faster cooking than a traditional fan oven and the flexibility to cook a full meal at once.
Ninja has a strong reputation in the UK for well-built, high-performing small appliances, and this model follows that pattern. It feels very much like a premium air fryer, both in price and in feature set, and owners have rated it highly overall.
If you’re looking to replace or reduce your oven use with something quicker, easier to clean and more versatile, this model is clearly pitched at you.
The Ninja Double Stack SL300UK is ideal for families and couples who cook most evenings and want to speed up weekday meals. The two baskets give you enough space to cook a main and sides together, so it suits anyone who’s regularly juggling chips, chicken and veg in the oven.
It’s a strong option if you’re trying to cut down on oil without giving up crispy results. The air fry technology uses hot air rather than deep fat, making it a healthier choice for regular fakeaways and snacks.
This is a premium-priced air fryer, so it suits buyers who are happy to pay more for extra versatility rather than simply picking the cheapest model. First-time air fryer users will still find it approachable thanks to straightforward button controls and a clear LCD display, but it’s particularly appealing if you want to do more than just chips, with functions for roasting, baking and dehydrating.
If you live in a smaller home or have limited worktop space, the tall, relatively compact footprint will be a big plus. You get the convenience of two baskets without needing a huge horizontal appliance.
The standout strength here is the dual-basket design in a stacked layout. You can cook different foods at the same time without flavours mingling, but the footprint stays narrower than many side‑by‑side dual air fryers, which is great for tighter kitchens.
Cooking performance should be strong thanks to the 2470W power and temperatures up to 240°C. That, combined with air frying, means fast heat-up times and crisp results on everything from chips to chicken wings, often noticeably quicker than a fan oven.
Versatility is another big plus. As well as standard air frying, the SL300UK can roast, bake and dehydrate, so you can handle everything from Sunday roast potatoes to homemade dried fruit and veggie crisps. It’s a good way to experiment beyond the usual frozen favourites.
Everyday usability has clearly been considered. Buttons and an LCD display make settings easy to see and change, there’s a timer to prevent overcooking, and cool-touch handles plus cool-wall technology help keep things safer around children. Non-stick, dishwasher-safe components also make cleaning up much less of a chore.
The inclusion of an anti-odour filter is a nice touch, helping keep cooking smells under control in open-plan spaces, and access to a recipe guide and app with hundreds of ideas means you’re unlikely to run out of inspiration.
The main drawback is price: this is not a budget air fryer, so if you just want something basic for the odd portion of chips, you may struggle to justify the extra spend on dual baskets and multiple functions.
Although the tall design saves space front to back, it is still a fairly chunky appliance at 38cm high, so it may feel imposing under low wall cupboards or on very shallow worktops.
There’s no dedicated keep-warm function, which some rivals offer. You can work around this with low temperatures and short timings, but it’s not as convenient if family members eat at different times.
Cord storage is also missing, and with a cable under a metre long, you may be slightly limited on where exactly you can position it relative to your sockets.
Day to day, the Ninja Double Stack SL300UK is designed to be straightforward. The control panel uses clear buttons and an LCD screen, so selecting temperature, time and function is simple even if you’re new to air frying. Once you’ve set it, the built-in timer helps avoid overcooking and lets you get on with other jobs.
The two baskets slide out on sturdy handles that stay cool to the touch, and the cool-wall body helps reduce the risk of accidental burns, which is reassuring in busy family kitchens. Non-slip feet keep the unit stable when you’re pulling drawers in and out.
Cleaning is one of the nicer parts of ownership. The non-stick finish on the cooking components means most residue wipes off easily, and the dishwasher-safe parts save you from scrubbing trays at the sink. That’s especially helpful if you’re using it daily for messier foods like marinated chicken or sausages.
The relatively short 0.89m power cord means you’ll want it close to a socket, but once in place, it’s the kind of appliance that will likely stay out on the worktop because of how often you’ll reach for it.
With 2470W of power and a maximum temperature of 240°C, the SL300UK is built for fast, high-heat cooking. It can cook significantly quicker than a standard fan oven, especially for smaller portions, which makes a real difference on busy evenings.
The dual-basket layout is the core feature. Having two separate cooking zones lets you prepare different elements of a meal at once, helping everything reach the table together. For example, you can roast vegetables in one drawer while crisping up chicken or fish in the other, avoiding the compromises that come with sharing a single tray.
Beyond basic air frying, the appliance supports roasting and baking, so you can use it as a mini-oven for traybakes, muffins or reheating leftovers. The dehydrate function is particularly useful if you like to batch-prep healthy snacks, from dried apple rings to vegetable crisps, using low, steady heat.
Practical extras round out the package. The anti-odour filter helps keep stronger smells, like fish or bacon, from lingering. Auto power-off adds a layer of safety if you forget to switch it off after a cycle. Dishwasher-safe parts, non-stick coatings and a recipe guide all reinforce the sense of a well-thought-out, feature-rich cooker that encourages you to use it often.
While it doesn’t have smart connectivity or app control of the appliance itself, the companion recipe app offers over 300 ideas tailored to Ninja cooking, which is a real bonus if you want to get more ambitious with what you cook.
The Ninja Double Stack SL300UK sits at the premium end of the air fryer market, and its price reflects that. You are paying more than you would for a simple single-drawer model, but in return you get two independently usable baskets, strong power, high maximum temperatures and additional functions like dehydration.
Given the solid specification, thoughtful safety features and ease of cleaning, it offers good overall value for households that will use it several times a week. The ability to replace or reduce oven use can also help keep energy costs in check over time, which adds to its long-term appeal.
The strong user rating and substantial number of reviews indicate that most owners feel it delivers on its promises, which is reassuring when you’re spending more on a premium appliance. If your budget allows and you’ll take advantage of the dual baskets and extra cooking modes, it justifies its price well. If you only fry occasionally, a simpler, cheaper model may be more sensible.
The Ninja Double Stack SL300UK is a well-designed, high-performance air fryer that makes a strong case as a genuine oven alternative for everyday cooking. Its stacked dual-basket layout is particularly appealing if you’re tight on counter space but still want the flexibility to cook a full meal at once.
Powerful heating, high temperatures and multiple cooking modes mean it handles everything from quick frozen snacks to roasts and homemade dried fruit with confidence. Safety features, easy cleaning and a helpful recipe ecosystem make it straightforward to live with, even for air fryer newcomers.
It is on the pricey side, and the absence of a keep-warm mode plus the short cable are minor niggles. But for busy households that want faster, healthier, multi-dish cooking in a relatively compact footprint, this is an excellent choice and one of the more versatile air fryers you can buy.
