Ninja SL300EU vs SL400EU vs SL451EU: DoubleStack Choices

Quick decision: Choose SL300EU when two 3.8-litre drawers fit the meal, SL400EU for two larger 4.75-litre drawers, and SL451EU when the digital food probe is worth the extra component. Copper and white are finish choices within their stated model families.

Exact review	Market and vessel	Useful distinction / offer
SL300EU	EU · 7.6 L, two 3.8-L drawers	The smaller DoubleStack saves width by stacking the drawers. Choose it when cupboard height and forward drawer access work in your kitchen; four rack levels still share two zone settings.
SL400EU	EU · 9.5 L, two 4.75-L drawers	The gray DoubleStack XL increases capacity over SL300EU. GRIS is a French colour description used in the old catalogue, not proof of a separate cooking platform.
SL400EUCP	EU · 9.5 L, two 4.75-L drawers	Choose the copper finish for appearance and the included package, rather than expecting four independent temperatures. It still has two controlled drawers with an optional rack in each.
SL400EUWH	EU · 9.5 L, two 4.75-L drawers	This white DoubleStack is the tall, narrow alternative to a side-by-side white AF400EUWH. Compare operating depth and drawer removal before choosing by colour alone.
SL451EU	EU · 9.5 L, two 4.75-L drawers	The European Smart Cook DoubleStack adds a probe to the stacked layout. Its 9.5-litre electrical variant must not be sold through an unlabelled US SL451 ten-quart link.

Four levels, two programmes

A rack in each drawer creates four cooking positions. It does not create four temperatures or four separate finish times; pair foods with compatible instructions inside a shared drawer.

Do the operating-space check

Measure width, height, ventilation and the space needed to remove a hot drawer. A slimmer footprint claim does not mean the appliance is shallower than every side-by-side option.

EU and US Smart models

SL451EU and US SL451 have different regional identities and ratings. The US ten-quart offer is labelled separately in the US review, rather than attached to a European model name.

What this comparison does and does not establish

These are specification and workflow differences, not results from a comparative cooking test. Select the exact regional model, check the supplied parts and seller condition, and compare complete delivered offers. We have not measured browning, noise, reliability or energy consumption side by side.

Choose by your kitchen and meals

Ninja Air Fryers: Model Reviews and Buying Guide · Ninja Air Fryers by Household: Portions, Meals and Timing · Ninja Air Fryer Size Guide: Baskets, Pots and Counter Space · Ninja Air Fryer Types: Drawers, Glass, Grills and Multicookers · Ninja Buying Priorities: Cleaning, Controls, Materials and Value.

Sources and review method

Clara Bennett checked the regional model information on October 24, 2026. This is a specification-led assessment; we have not bought or bench-tested these appliances. Meal-fit suggestions are editorial judgments, not measured serving or cooking-speed guarantees. Manufacturer performance and materials claims apply only to their stated model, components and test conditions. Prices, condition, accessories and warranty terms can change.

About the Author

Clara Bennett

I write practical, model-specific air fryer reviews and comparisons. I focus on usable capacity, household fit, cleaning, materials, day-to-day ownership and value so you can choose the right appliance with fewer surprises.

Read my full profile and review method