Ninja
Ninja Double Stack XL SL400UK
9.5L, stacked dual drawer, Grey
Editorial review Reviewed 19 October 2026 How we assess products
The Double Stack puts its 9.5 litres above each other instead of side by side. At 28cm wide, it solves a different problem from a small-capacity air fryer: a family can keep two zones while freeing up counter width. The supplied racks let you separate a protein and side in each drawer. Layered cooking is useful, but it adds racks to load, lift and wash. Good chips and mixed meals are within its reach; do not treat four levels as a promise that every food will brown evenly without attention. It is audible in use, tall, and considerably deeper than its narrow front suggests. Hand-washing the non-stick drawers can help preserve their finish.
Key facts
Use these figures as a starting point. If a specification is critical to your choice, confirm it on the retailer or manufacturer page before buying.
- Colour
- Grey
- Capacity
- 9.5L
- Type
- Stacked dual-drawer
Will it fit?
Measure the available width, depth and height, then allow for any clearance stated in the product instructions.
- Width
- 28cm
- Depth
- 47cm
- Height
- 38.5cm
Strengths
- Two stacked 4.75L drawers retain 9.5L capacity in a 28cm-wide body
- Two racks create four cooking levels and help keep foods apart
- SYNC and MATCH coordinate independently set mains and sides
- Six modes include reheat and dehydrate, with capable crisping for mixed meals
- Removable drawers and plates are dishwasher-safe; hand-washing helps preserve their finish
Limitations
- Its 47cm depth and ventilation space still need a generous counter
- Rack access takes more handling than a simple single-layer basket
- Fan noise and occasional uneven browning mean checking and rearranging food still matter
- Check overhead clearance as well as the 38.5cm appliance height
- For a kitchen constrained by width, it is a useful way to keep two drawers. For easier access and a shallower appliance, the AF400UK remains our first choice where its wider footprint works.
- At our 19 October 2026 check, the probe-equipped SL451UK was £199 direct versus roughly £269–£270 for this standard SL400UK. Compare that separately verified model before paying more; it is the current stacked choice in our Air Fryers guide.