Ninja Double Stack XL Review UK 2026
Quick verdict
Score: 7.7/10
Best for: Faster, lower-oil everyday cooking and reheating, cooking two foods at once
Not for: Large family roasts and big-batch cooking, where a full-size oven still wins on capacity
Bottom line: A practical air fryer (9.5L, dual zone, 6 functions) that crisps food fast with little oil and costs less to run than an oven.
The Ninja Double Stack XL is a 9.5L vertical air fryer with two separate drawers for cooking, and it includes a digital cooking probe. It is positioned for practical batch cooking, letting two different foods run at the same time using each drawer and its own rack, with separate timings for portions. It is intended for 8 portions, but the vertical design can feel bulky and it restricts oversized cooking that would not fit within a single drawer. Overall, it is a flexible option for meal prep.
Key specifications
| Feature | What it means |
|---|---|
| 9.5L capacity | Holds multiple portions |
| Dual-zone drawers | Separate foods |
| 6 functions | Variety of cooking modes |
| Digital cooking probe | Monitors doneness |
| 2 racks | Supports layered placement |
Pros
- 9.5L capacity
- Dual zone - cook two foods at once
- 6 cooking functions
- Faster and cheaper to run than a full-size oven
Cons
- Takes up worktop space (dual-zone models are bulky)
- Cooks smaller batches than a full-size oven
- Some foods still need a light spray of oil to crisp up
Capacity and Size
Capacity is a key factor for choosing this air fryer, especially because it is built as a dual-drawer air fryer with a stated 9.5L capacity. This size is aimed at cooking for multiple portions, and the product title specifies up to 8 portions. The space is divided across two drawers, with each drawer featuring its own rack, which allows different foods to be cooked separately rather than combined in one basket. The unit is designed around four cooking levels.
Cooking Performance and Functions
With dual-zone cooking as its main feature, the Ninja is built around two drawers that can be run independently. This is designed to support different cooking stages at the same time. It offers 6 cooking functions, and it includes a digital cooking probe for more controlled doneness checks during cooking. The vertical design uses 4 cooking levels, with 2 drawers and 2 racks, so loads can be arranged for thicker or thinner portions. Preheating and spacing are important, because overcrowding can slow browning. Overall, results depend on selecting the right function, using the probe checks when needed, and leaving sufficient airflow space around the food.
Single or Dual Zone
The air fryer uses dual-zone cooking, with two drawers that can be run independently so different foods can be cooked at the same time. It offers 9.5L capacity across the unit, split between the two drawers, with the drawers able to work together or separately depending on the meal plan. This flexibility can reduce waiting time between cooking and serving. Single-zone use limits the total airflow control options if requirements change.
Ease of Use and Controls
The Ninja is straightforward to operate day to day. Its vertical dual drawer layout creates two separate cooking zones within one body, which helps when different parts of a meal need different timings. Digital controls are simple to use, with six cooking functions available, so most cooking starts by choosing a function, setting a level, and starting the programme. A digital cooking probe supports more guided doneness, but results still depend on placing the food correctly across the two drawers. With four cooking levels and a two-drawer layout plus racks, the setup offers flexibility, although arranging racks evenly takes a little practice.
Cleaning and Maintenance
Cleaning and Maintenance is fairly manageable for the air fryer, largely because the dual-drawer vertical design helps keep food residues contained within each drawer. After cooking, allow the unit to cool, then slide the two drawers out carefully. Removable racks inside each drawer can be washed by hand using warm soapy water, and any remaining mess on the surfaces should be wiped clean. Any drips on the drawer base should be removed using a damp cloth. The probe, if used, should be wiped gently.
Noise and Energy Use
Noise levels and energy use will vary with the cooking function, the portion size, and how often the drawers are opened, because the air flow needs time to recover heat between steps. In everyday use, the SL451UKSD's dual drawer design means both compartments work through the same general airflow cycle, so cooking two items at once can be more efficient. When only one drawer is used, the other drawer remains in place, which can reduce waste but may not change sound output much. Energy use is best judged by meal frequency, since shorter batches repeat preheat and cook stages.
Who Is This Air Fryer For?
The Ninja Double Stack XL suits people who want to cook two different foods at the same time, using its dual-zone, dual-drawer design with a 9.5L total capacity split across two drawers. It is a good fit for households that regularly cook for up to 8 portions, because the total cooking space is designed to handle larger meals. Home cooks who prefer separating foods to keep flavours distinct will also find the four cooking levels practical, especially with its vertical stacking layout. It can work well for people who already use multiple trays, since the double stack supports multiple layers, but it may be space-heavy for smaller kitchens.
Where to Buy in the UK
Where to buy the Ninja in the UK is often the main question, because this model uses a vertical dual-drawer design, includes a digital cooking probe, and has a 9.5L capacity. It can typically be found via major UK retailers that stock The air fryer and SharkNinja appliances, as well as online marketplaces such as Amazon UK, John Lewis, Currys, AO, and Argos. Before purchasing, check that the listing matches the exact model number "SL451UKSD" and confirm the included items align with the product title, including the digital cooking probe, 2 drawers and 2 racks. Delivery details should also be reviewed, especially if the exact 9.5L version is not listed, since availability can vary by retailer.
Frequently Asked Questions
Is the Ninja worth it?
For faster, lower-oil cooking of chips, chicken, veg and reheats, the air fryer earns its place with 9.5L capacity and two drawers so you can cook two things at once. It is also cheaper to run than heating a full-size oven - check the current Amazon UK price, as it changes often.
Is this air fryer big enough for a family?
The Ninja has 9.5L capacity, split across two drawers, so the usable space per drawer is smaller than the total suggests. As a rough guide, 4-5L suits 1-2 people, 6-8L suits 3-4, and larger or dual-drawer models suit families of 4 or more.
What are the downsides of the Ninja Double Stack XL?
Air fryers take up worktop space (dual-zone models are bulky), cook smaller batches than a full oven, and some foods still need a light oil spray. They are best for crisping and reheating rather than replacing every oven job, which is why they suit some kitchens better than others.
Is the air fryer cheaper to run than an oven?
For small and medium portions, usually yes - this air fryer heats a much smaller space than a full-size oven and cooks faster, so it uses less energy. For large meals that fill a big oven anyway, the saving is smaller. Exact cost depends on its wattage and your tariff.
Can the Ninja cook two things at once?
Yes - the air fryer has two separate drawers, so you can cook two foods at different temperatures and times, and finish them together. It is ideal for a main and a side, though it takes up more worktop space than a single-drawer model.
What can you cook in the Ninja?
The air fryer has 6 cooking functions covering jobs like air-fry, roast, bake, grill and reheat. Beyond chips it handles chicken, fish, veg, bacon and reheating leftovers crisply; baking and dehydrating are possible on models that offer those modes.
Is the Ninja Double Stack XL easy to clean?
The drawer and crisper plate wipe or wash clean; non-stick coatings make this easier. Clean it after each use, as baked-on grease is harder to remove later.
Do you need oil in this air fryer?
Little or none - the Ninja circulates hot air to crisp food, so most things need only a light spray of oil or none at all. Naturally fatty foods like sausages need no added oil, while a fine mist helps fresh chips and breaded items crisp up.