Comparison · Kitchen · 2 models
Ninja Air Fryer 3.8 L (AF100UK) vs Ninja Double Stack 7.6 L (SL300UK): one drawer or two?
Same brand, same 28 cm width, same 3.8-litre drawer — one machine has one of them and the other stacks two. The Double Stack is 3.5 cm taller, 8 cm deeper, more than twice the weight and 900 watts hungrier. For two people the question is whether you cook one thing or two at a time; for a small kitchen it is whether the extra height fits under the cupboards.
Quick answer
Side by side
| Model | Basket capacity | Width | Height | Weight | Power | Where to buy |
|---|---|---|---|---|---|---|
| Ninja Air Fryer AF100UKone 3.8 L drawer — one thing at a time | 3.8 L | 28 cm | 35 cm | 4.4 kg† | 1550 W | View listing |
| Ninja Double Stack 2-Drawer Air Fryer 7.6 L (SL300UK)two 3.8 L drawers stacked — a main and a side together | 7.6 L | 28 cm† | 38.5 cm | 9.76 kg | 2470 W | View listing |
Scroll sideways to see every column
† Figure from a retailer listing or otherwise awaiting confirmation from the manufacturer; other figures come from manufacturer manuals and leaflets.
Figures are Ninja’s. The AF100UK’s weight is 4.4 kg in its manual and 5.2 kg on Ninja’s product page; the SL300UK’s page gives 28 cm wide and 42 cm deep in its product bullets and 28.6 × 45.2 cm in a spec table. We show the bullet figures and flag both conflicts in the product data.
The portion arithmetic
one 3.8 L drawer — one thing at a time
Ninja Air Fryer AF100UK
- Basket capacity
- 3.8 L
- Width
- 28 cm
- Height
- 35 cm
- Weight
- 4.4 kg†
- Power
- 1550 W
Check price on Amazon.co.uk
The AF100UK is one 3.8 L basket, which Ninja rates for a 1.35 kg chicken or 900 g of chips: two adult main portions in one round, or a shared main and nothing else. For a couple who air-fry one thing — chips with something from the oven, a tray of vegetables, a chicken on Sunday — it is exactly enough, and it is the machine most people picture when they say “air fryer”.
Strengths
- 3.8 L basket cooks for two in one go, with room for a small chicken
- Basket and crisper plate are dishwasher-safe
- Dehydrate mode on top of air fry, roast and reheat
Limitations
- 35 cm tall — check the gap under a wall cupboard
- Ninja's own site now points to the newer AF150UK Max; this is an older model still sold on Amazon
- No preset programmes, only manual time and temperature
Good for
- two people
- a shared side of chips
- someone who wants a dehydrate function
Look elsewhere if
- a worktop narrower than 30 cm
- anyone who wants one-touch presets
two 3.8 L drawers stacked — a main and a side together
Ninja Double Stack 2-Drawer Air Fryer 7.6 L (SL300UK)
- Capacity
- 7.6 L
- Width
- 28 cm†
- Height
- 38.5 cm
- Weight
- 9.76 kg
- Power
- 2470 W
Check price on Amazon.co.uk
The Double Stack is two of those drawers, each rated by Ninja for a 1.2 kg chicken or 400 g of chips, one above the other, with 7.6 litres in total and a “serves up to six” claim. Its two functions that the single cannot do are SYNC — set different times and temperatures for each drawer and both finish together — and MATCH, which copies drawer 1’s settings to drawer 2 for a double batch of one thing. Two stacked meal racks give four layers when you want quantity rather than variety.
The honest test is your last ten air-fryer dinners. If most were one item, the second drawer is a shelf you will store things in. If most were an item plus a side, it is the difference between eating together and eating in shifts.
Strengths
- Two independent drawers, SYNC to finish together, in a 28 cm-wide body
- Four cooking levels with the two racks; 40–240 °C range
- Drawers, plates and racks dishwasher-safe
Limitations
- 38.5 cm tall plus Ninja's 15 cm clearance — check the gap under wall units
- 9.76 kg: it lives where you put it
- 2,470 W is a kettle and a half on the circuit
Good for
- two people who cook a main and a side at once
- a narrow run of worktop that cannot take a 40 cm-wide dual
- families of up to six
Look elsewhere if
- a cupboard gap under about 45 cm at the back of the worktop
- one person cooking one thing
- anyone who wants to put the machine away
The footprint: same width, more of everything else
Both machines are 28 cm wide, which is the unusual part of this comparison. A conventional two-drawer machine puts the drawers side by side and takes about 40 cm of worktop; Ninja’s own comparison calls the Double Stack 25% slimmer than its Dual Zone AF300. What the stacking costs is depth and height: 42 cm deep against 34, and 38.5 cm tall against 35.
Depth matters on a shallow worktop or a breakfast bar — 42 cm on a 60 cm worktop leaves 18 cm in front, and the lower drawer opens toward you. Height matters under wall cupboards. The gap is usually 45 to 50 cm; both machines fit in height, and neither fits with Ninja’s 15 cm clearance rule applied literally. In practice both are pulled to the front edge to cook, and the 38.5 cm machine leaves less room for a cupboard door above it.
Weight, power, heat
The Double Stack is 9.76 kg — a machine that lives where you put it. The AF100UK is 4.4 kg by its manual (5.2 kg by Ninja’s page), which one person moves in and out of a cupboard.
Power: 2,470 W against 1,550. Both run from a 13 A socket, but the Double Stack draws about 10.7 A on its own, so it should not share an extension lead with a kettle. Temperatures: the AF100UK runs 40 to 210 °C across Air Fry, Roast, Dehydrate and Reheat; the Double Stack adds Bake and a Max Crisp mode fixed at 240 °C for frozen food, with the other functions capped at 210 °C.
Cleaning and guarantee
Both have dishwasher-safe drawers and crisper plates, and the Double Stack’s racks go in too; neither main unit does. Both carry Ninja’s two-year guarantee on registration within 28 days, UK and Ireland.
Availability
The AF100UK is an older design: Ninja’s own website redirects its page to the newer AF150UKCP Air Fryer Max, though the AF100UK is still sold. If you want the single-drawer Ninja and the AF100UK has gone, the successor is the like-for-like replacement. The Double Stack SL300UK is current, with a larger 9.5 L XL version above it.
Which one, by kitchen
- One or two people, one thing at a time, a cupboard to store it in: AF100UK.
- Two people who want a main and a side finishing together, worktop to spare: Double Stack.
- A narrow worktop that cannot take a 40 cm dual, and a 50 cm cupboard gap: Double Stack, pulled forward to cook.
- A gap under 45 cm and no other place for it: AF100UK, or the Crispi that stores in pieces.
Sources
Facts checked 24 September 2026
- SharkNinja — Ninja Air Fryer AF100UK owner's guide, hosted by manuals.co.uk — Product manual, checked 23 September 2026
- Amazon.co.uk listing (Ninja AF100UK), seller content by Ninja — Retailer listing, checked 23 September 2026
- Ninja UK — Air Fryer AF100UK product page, archived 2025-05-15 (live URL now redirects to the AF150UKCP) — Manufacturer documentation, checked 24 September 2026
- SharkNinja UK — Ninja Double Stack SL300UK product page (live) — Manufacturer documentation, checked 24 September 2026
- Ninja UK — Double Stack SL300UK product page with FAQs, archived 2025-07-31 — Manufacturer documentation, checked 24 September 2026
- Ninja — SL300UK Series instruction booklet (PDF via Ninja's Flixmedia syndication) — Product manual, checked 24 September 2026
- Amazon.co.uk listing (Ninja) — Retailer listing, checked 24 September 2026
Is a two-drawer air fryer worth it for two people?
Only if you cook two things at once and want them to finish together. Two people who air-fry one thing — chips, a tray of vegetables, a chicken — are served by one 3.8 L drawer, which Ninja rates for a 1.35 kg chicken or 900 g of chips. Two people who want fish in one drawer and chips in the other, finishing together, need the Double Stack's SYNC function. That is the whole decision; the rest is space.
Does the Double Stack fit under wall cupboards?
It is 38.5 cm tall, which Ninja says is designed to fit under cabinets, and the gap under a standard UK wall unit is 45 to 50 cm. But Ninja's booklet asks for 15 cm of clearance above and around the machine while it runs — 53.5 cm in total — so under a cupboard it should be pulled to the front edge of the worktop when it is on. The AF100UK, at 35 cm, has the same problem 3.5 cm less badly.
How many portions from a 3.8 L drawer?
Ninja's own figures: the AF100UK's 3.8 L basket takes a 1.35 kg chicken or 900 g of chips; each of the Double Stack's 3.8 L drawers takes a 1.2 kg chicken or 400 g of chips — Ninja's portion figures differ between the two machines for the same nominal volume, probably because the stacked drawers are shallower. Two adult portions per drawer is the practical rule.
Is the Double Stack narrower than a normal dual-drawer air fryer?
Yes — that is its point. Side-by-side duals put two drawers next to each other and are around 40 cm wide; the Double Stack puts them one above the other in a 28 cm body, which Ninja describes as 25% slimmer than its own Dual Zone AF300. It is the same width as the single-drawer AF100UK and gains its capacity in height and depth instead.
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