Ninja
Ninja Double Stack XL Smart Cook SL451UK
9.5L stacked drawers · Grey · Digital probe
Editorial review Reviewed 19 October 2026 How we assess products
The SL451UK adds an integrated digital cooking probe to the 9.5L Double Stack layout. Its two 4.75L drawers and two racks allow four cooking levels in a 28cm-wide, 47cm-deep body. Six cooking modes, SYNC and MATCH help coordinate meals. At our 19 October 2026 check it cost £199 direct, less than the standard SL400UK at about £269–£270. Use the probe for suitable meat and fish, with correct placement; it does not check how evenly every food browns. Allow ventilation and overhead access, check browning and use the probe as instructed. The drawers and plates are dishwasher-safe; hand-clean the probe.
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.
- Capacity
- 9.5L
- Power
- 2,470W
- Type
- Stacked dual-drawer with probe
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 allow four cooking levels and help keep foods apart
- Six modes with SYNC and MATCH coordinate independent drawer settings
- An included digital cooking probe helps monitor suitable meat and fish
- At the checked direct price, it offers better value than the standard SL400UK
Limitations
- The 47cm depth and ventilation allowance still need a generous counter
- Rack access adds lifting and cleaning compared with a simple single-layer basket
- Stacked food still needs checking for even browning
- The probe needs correct placement and hand-cleaning; it does not make every food automatic
- The probe measures core temperature where you place it; keep checking the colour and texture of other foods.
- Choose the SL451UK when a narrow family air fryer and included probe suit you. Compare the standard SL400UK only if it becomes cheaper; Salter VertiCook View is the lower-cost stacked option with viewing windows. AF400UK remains easier to access if a wider, shallower dual drawer fits your worktop.
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