iPhone Duo: Apple’s Foldable iPhone Is Here, And The Hinge Has More Than 100 Parts

Apple did not just fold a phone in half. It rebuilt the inside of one to make the fold survivable, and then spent a chunk of its keynote explaining the adhesive.

The iPhone Duo is official. It is Apple’s first foldable, its first iPhone with two displays, and, when open, the thinnest iPhone the company has ever made. It starts at $1,999 for 256GB and reaches 2TB at the top of the range. Pre-orders open on 16 October, with the phone on sale from 23 October.

Here is everything Apple announced, and the details that matter more than the ones that made the slides.

The Hardware: Titanium, Ceramic Shield, And A Very Serious Hinge

The two halves join into a single continuous frame, with the same aspect ratio maintained across both displays so content does not distort as you move between them. Apple made a point of the transition between open and closed feeling fluid rather than mechanical.

The frame is machined and polished grade 5 titanium. The back uses Ceramic Shield, the front Ceramic Shield 2 with three times better scratch resistance, and the whole device carries an IP68 rating, which is notable given that water ingress has historically been the weak point of any device with a moving seam.

Two colours at launch: Star White and Night Sky. Close enough to the white and dark blue that leaked, with better names.

To fit everything in, Apple has packaged components into the camera plateau, which is how a device with two screens and two batteries manages to be the thinnest iPhone ever when unfolded.

Inside The Hinge

This is where Apple spent its engineering budget, and it is worth going through properly.

The custom hinge uses more than 100 precision components. Its job is twofold: hold the display genuinely flat when open, and control the folding motion so the screen is never stressed at the wrong point.

Behind that sits a multi-layer lamination design using viscoelastic adhesives, which allow the display’s layers to glide against one another as the device folds. Apple’s own comparison was pages in a book. The point is that rigid bonding is what causes foldable displays to distort and eventually fail, so letting the layers move independently is the fix.

Underneath, a titanium plate forms the bottom layer for durability, with carbon fibre support plates creating a stiff but lightweight base for the display to rest on.

None of this will make a difference to how the phone feels on day one. All of it will determine how it feels in three years, which is the only durability question that has ever mattered for a foldable.

The Displays: 7.6 Inches Inside, 5.4 Outside

The inner display measures 7.6 inches. Apple says that is 50% larger than the iPhone 18 Pro Max and 80% larger than the iPhone 18 Pro.

The outer display is 5.4 inches and delivers 90% of the screen area of the iPhone 18 Pro. That is the number that decides whether this works as an everyday phone. A foldable with a cramped, letterboxed cover screen forces you to open it constantly. At 90% of a Pro, the Duo should be perfectly usable closed.

Apple Pencil support is not available at launch. Apple says the Duo will support Apple Pencil with USB-C on both displays later this year, for notes, sketching and marking up documents.

The Crease, And How Apple Attacked It

Apple created a custom nano texture finish for the display surface that cuts glare and reflections.

Separately, and more interestingly, there is a micro lens texture produced using maskless laser lithography, which writes each lens pixel by pixel. Apple describes the result as a perceptually flat matte surface that minimises the visibility of the fold crease while still feeling premium under a finger.

Read that carefully. Apple has not eliminated the crease. It has engineered a surface that makes the crease harder to perceive. That is a meaningfully different claim, and it is the one thing every hands-on review will be poked at. Whether it holds up under a window on a bright day is the question.

The Software: iOS Rebuilt For Two Screens

This is the part rivals have consistently got wrong, and Apple has clearly put the work in.

Controls have moved. Essential controls now sit at the sides of the display, within thumb’s reach, rather than at the top of a screen you cannot span with one hand.

The dock is vertical. On the inner display, the Home Screen dock orients vertically, and the status bar has been redesigned to tuck into the corner.

Transitions are continuous. As you open the device, the software moves between outer and inner displays with controls holding a consistent position while content scales up. You do not lose your place.

It understands being propped. iOS adapts to how the device is angled or stood up, and it can be used partially folded. In that state, content slides away from the crease, where taps are harder to register accurately. That is a genuinely thoughtful detail.

Audio adapts too. Custom audio tuning compensates for the changing distance between the speakers depending on how the device is positioned.

Real multitasking. You can run two apps side by side, or open the same app twice. Swipe up from the bottom to switch apps, or pair two apps together so they reopen as a set later.

Standby mode. A new Standby mode adds widgets for music, calendar and weather, and Apple pitched the propped-open device as a bedside clock with a soft glow.

The two-instances-of-one-app feature is the one power users will notice. Two Safari windows, or two Mail accounts side by side, is the kind of thing that makes a large screen worth carrying.

The Cameras: Two On The Back, Two On The Front

The rear system uses the 48MP Fusion main camera design Apple uses elsewhere in the line-up, paired with a 48MP Fusion ultra wide, the same one in the iPhone 18 Pro. Upgraded Photographic Styles are supported.

There is no telephoto. That is the single clearest compromise in the whole device, and it puts the Duo behind the iPhone 18 Pro for anything at distance. In a phone this expensive, it will bother some buyers a great deal.

What the Duo offers instead is a camera that can stand up by itself, which Apple leaned into with 4K Dolby Vision HDR time lapses shot without a tripod.

On the front, there are two:

• A 12MP Center Stage camera in the outer display, which lets you preview a selfie before taking it
• A FaceTime camera hidden behind the inner display, working whether the device is fully open or propped on a surface

The two can dual capture front and rear scenes at the same time.

The Camera Software Features Nobody Predicted

Duo FaceTime. Someone else can join a video call from the outer display. Two people, one phone, one call, each with their own screen.

Smart Take. The camera tracks a scene and fires automatically once everyone in a group shot is ready. No timer, no running back into frame.

Animations for children. The outer display can play animations to hold a child’s attention while you shoot from the other side. Every parent who has tried to photograph a toddler will recognise the problem immediately.

These are the features that justify two screens rather than merely tolerate them, and they are more persuasive than any spec on the sheet.

Touch ID Returns

The Duo has Touch ID built into the side button, and can also be unlocked using an Apple Watch.

Apple made no mention of Face ID on this device, which strongly suggests the TrueDepth array could not be accommodated alongside an under-display camera in a body this thin. If confirmed, this is the first flagship iPhone in years to lead with a fingerprint sensor.

Depending on your view, that is either a welcome return or a step backwards on a $1,999 phone. We will confirm the Face ID position once the full technical specifications are published.

Performance And Connectivity

The Duo runs the A20 Pro, the same chip as the iPhone 18 Pro, with no cut-down variant. Apple quotes up to 35% higher sustained performance than the iPhone 17 Pro.

It also carries the new C2 modem, which Apple says is up to 50% faster than the C1X, uses up to 15% less battery, and adds 5G mmWave support in the US. AI algorithms improve everyday cellular reliability, including faster reconnection in weak coverage.

Two notes for readers outside the US. The mmWave support is US-only, and UK networks have not deployed it meaningfully. More importantly, the iPhone Duo is eSIM only worldwide. There is no physical SIM tray anywhere, including the UK. All major British networks support eSIM now, but if you swap SIMs while travelling or rely on a cheap physical local SIM abroad, this changes your routine.

Battery: Two Cells Acting As One

Each half has its own battery, and Apple says they operate together as a single unit.

Usage	Rated battery life
Video on inner display	Up to 31 hours
Video on outer display	Up to 44 hours
Both screens used equally	Up to 24 hours

Fast charging hits 50% in around 20 minutes, and five minutes on the charger yields up to five hours of video playback on the outer display.

The 24-hour mixed-use figure is the realistic one to plan around, and it is respectable for a first-generation foldable. It is worth noting it sits below the iPhone 18 Pro’s 36 hours, which is the price you pay for driving a 7.6-inch panel.

Accessories

Two at launch. A Duo Folio case with a built-in kickstand, and an iPhone Duo Case made of two separate parts that wrap around each half of the device.

The kickstand is the more interesting of the two, given how much of the software assumes the device is propped up.

Price And Release Date

The iPhone Duo starts at $1,999 for 256GB, with storage running up to 2TB. The full storage ladder tops out at $3,199.

Pre-orders open 16 October, with availability from 23 October. That is roughly a month behind the iPhone 18 Pro, in line with what had been expected.

UK pricing had not appeared on Apple’s store at the time of writing. Recent generations have tracked close to dollar parity once VAT is applied, which points to somewhere around £1,999 for the entry model, but the figures on Apple’s UK store are the only ones that count. We will update this article with confirmed UK pricing as soon as it is live.

The Verdict, Before Anyone Has Touched One

The Duo is a more complete first-generation product than it had any right to be. The software has been genuinely rebuilt rather than stretched, the multitasking is real, and the dual-screen camera features are the sort of thing that only becomes obvious once someone ships it.

The open questions are the ones no keynote can answer. How visible is the crease in daylight. How does a hinge with 100 components feel after a year in a pocket. Whether 24 hours of mixed use survives contact with real usage. And whether the missing telephoto is a compromise you notice weekly or forget about entirely.

At $1,999 with a 2TB ceiling, Apple has priced this to be bought rather than admired. Now it needs to survive being used. Everything else Apple announced is in our live blog of the event, and the naming and colours story is here.

Are You Pre-Ordering On 16 October?

Two screens, no telephoto, Touch ID instead of Face ID, and an eSIM-only design. That is a lot of trade-offs for a lot of money, but it is also the most interesting iPhone in a decade. Are you in on day one, or waiting to see how the hinge holds up? Tell us in the comments.