Apple’s first foldable iPhone, Duo, will open UK preorders at 1 p.m. on 16 October, with availability from 23 October, according to Apple’s UK listing. The 256GB Duo is listed at £1,999. Apple’s iPhone 18 Pro store page lists the 256GB Pro at £1,199 and Pro Max from £1,299. The published specifications show the main choice: Duo adds a large foldable screen and a wider multitasking layout, while the Pro models list a separate telephoto camera.

What the Duo adds

Duo opens to a 7.6-inch inner display and folds around a 5.4-inch outer display. Apple says the inner screen has 50 percent more display area than the iPhone 18 Pro Max. Its software supports side-by-side apps, and the specifications list support for Apple Pencil (USB-C). The device weighs 254 grams.

That design may suit someone who reads, writes or keeps two apps open on a larger screen while carrying one device. Apple shows it in several positions, including a hands-free angle for calls or video. It also folds into a shorter outer-screen phone for one-handed use. Those are uses Apple describes; they do not mean every iPad task transfers to the phone or that the foldable will suit every buyer.

Weight is another practical difference. Apple lists Duo at 254 grams, compared with 211 grams for iPhone 18 Pro and 249 grams for Pro Max. Duo is close to the Pro Max weight while adding a hinge and two displays. Buyers who carry a phone in a pocket may want to compare the folded dimensions before choosing.

The Pro models have conventional 6.3-inch and 6.9-inch displays, respectively. Duo’s 7.6-inch inner screen is larger when open, while its 5.4-inch outer display is smaller than either Pro screen. The choice is therefore about using two screen sizes and a hinge, not simply selecting the largest single display. Apple’s store lists Duo at £2,199 for 512GB, £2,599 for 1TB and £3,199 for 2TB. The £800 starting-price gap compares the two 256GB models; buyers choosing more storage should compare the capacity they would actually order.

Where the camera systems differ

Apple’s Duo specifications list a 48MP Fusion Main and a 48MP Fusion Ultra Wide. The main camera enables 2x optical-quality zoom, but Duo does not list a separate telephoto camera. Apple’s iPhone 18 Pro specifications list a 48MP three-camera system with a variable-aperture main camera and a dedicated 48MP Fusion Telephoto camera with 4x optical zoom and 8x optical-quality zoom. That is the clearest hardware difference for someone who often photographs distant subjects. It describes the listed lenses and zoom options, not a comparison of image quality.

Apple’s video-playback estimates are up to 31 hours on Duo’s inner display or 44 hours on the outer display, versus up to 34 hours on iPhone 18 Pro and 43 hours on Pro Max. These are manufacturer estimates, and Duo’s display modes are listed separately; they are not a direct real-world battery comparison.

Both phones use Apple’s A20 Pro chip. Duo also supports Apple Pencil (USB-C) and Split View. A buyer who regularly annotates, sketches or uses two apps side by side may value those features; someone who wants a conventional phone can keep the simpler one-screen form.

Concept illustration of two camera-lens groups, one adding a dedicated telephoto symbol, under TELEPHOTO TRADE-OFF.
Duo's specifications do not list a separate telephoto camera; the Pro specifications do. The concept illustrates hardware options, not measured image quality.

What to check before ordering

At the same 256GB starting storage, the UK listing puts Duo £800 above iPhone 18 Pro. Carrier prices and offers can differ. Apple’s listing shows Duo preorders opening on 16 October and availability from 23 October; the Pro models are already on sale. Duo is eSIM-only worldwide, so buyers who rely on a physical SIM should check carrier compatibility before ordering.

Apple’s specifications can compare screen format, camera hardware, weight and estimated playback time. They cannot settle how the hinge or inner display will hold up after years of use. Before spending more, compare the published features and local price with the way you use a phone, then look at both sizes in person if possible.