Ninja Double Stack XL SL400UK

If the appeal of an air fryer for two is finishing a main and a side together, the Double Stack XL solves it without the wide footprint of a side-by-side dual basket: Ninja stacks two 4.75L drawers (9.5L total) vertically, making it around 30% slimmer and about 38.5cm tall to fit under wall cabinets. It runs 2470W across six functions with two independently controlled zones, so chips and chicken can finish at the same time. The trade-off against the single-basket picks above is real: at roughly £199 it costs far more, needs cabinet clearance for its height, and 9.5L is more than two people usually need. We rank it third because that price drags its value score below the cheaper compacts, even though its performance and features are the strongest here; choose it only if simultaneous two-zone cooking genuinely matters to you.