Apple launched the iPhone Duo alongside the iPhone 18 Pro line-up in September 2026. If you are deciding between them, here is what Apple has confirmed, and what the choice really comes down to.
The core difference
The iPhone Duo is a foldable. Closed, it is a compact phone with a 5.4-inch outer display. Open, it becomes a 7.6-inch screen, which Apple says is the largest display ever on an iPhone and 50% larger than the iPhone 18 Pro Max. The iPhone 18 Pro and Pro Max are conventional slab phones.
If you want a bigger canvas for reading, video, gaming or working with two apps side by side, the Duo is the only iPhone that does it. If you do not, the Pro models are simpler and less expensive.
Displays
- iPhone Duo: 7.6-inch inner display with a nano-texture finish to reduce glare, plus a 5.4-inch outer display. Apple says the outer display has about 90% of the screen area of the iPhone 18 Pro, and both displays share the same aspect ratio so content scales between them. The inner display has an under-display front camera.
- iPhone 18 Pro / Pro Max: single display, in two sizes.
Chip and performance
Both use Apple's A20 Pro chip. Apple says the iPhone Duo has a custom vapour chamber for thermal management, and a dual-battery design. For day-to-day performance, you should not expect a meaningful difference between them.
Battery
Apple quotes up to 31 hours of video playback on the Duo's inner display and up to 44 hours on the outer display. Compare against Apple's published figures for the 18 Pro models on its comparison page, since battery claims depend on the test.
Cameras
The iPhone Duo has a 48MP Fusion main camera and a 48MP ultra wide camera. Because it folds, you can use the main cameras for selfies, with a preview on the outer display. The iPhone 18 Pro models have Apple's Pro camera systems; check Apple's comparison page for exact lens line-ups if telephoto matters to you.
Software
iOS 27 adds foldable-specific features on the Duo, including side-by-side apps and new ways to use the phone propped up in different positions. Apple Intelligence features are available on both.
Connectivity
The iPhone Duo is eSIM-only. If you rely on a physical SIM, check your carrier supports eSIM first.
Price
The iPhone Duo starts at $1,999 / £1,999 for 256GB and goes up to $3,199 / £3,199 for 2TB. The iPhone 18 Pro models cost considerably less. See Apple's site for current pricing in your country, and our iPhone Duo price guide.
Which is right for you?
Choose the iPhone Duo if you want a much bigger screen in a pocketable phone, you multitask on your phone, or you watch a lot of video. You also have to be comfortable paying a premium for a first-generation design.
Choose an iPhone 18 Pro if you want the familiar shape, a lower price, and immediate availability, which is likely to be easier than for a brand-new foldable.
Try before you buy
Apple Stores have the iPhone Duo on display, so you can try the fold, the hinge and the weight. If you decide it is for you, set up an alert and we will email you as soon as that store shows pickup stock: £5 for any configuration, or £10 for your exact one.