Apple folds and follows the new high-end smartphone format. Meet the Apple iPhone Duo

This year’s ‘September Event’ was something of a double whammy for Apple, which not only introduced the world to a shiny new CEO in the form John Ternus, but also unveiled the iPhone Duo, its first ever folding phone, alongside the new iPhone 18 Pro and 18 Pro Max, Apple Watch Series 12 and Ultra 4 and AirPods 5, plus iOS27. Ternus, who took over from Tim Cook earlier this month, had the privilege of standing on stage at Apple Park and casually saying ‘there’s one more thing’, the traditional prelude to an earth-shaking announcement.

So what’s the big deal? It wasn’t as if the Duo was unexpected (although some thought it would be called the iPhone Ultra). The physical form is certainly unconventional (although Apple was beaten to the wallet/passport size ratio by both Samsung and Xiaomi), but what really matters is how it performs and what Apple has done to make the two-screen format feel essential rather than an impressive gimmick.

After all, this is the first change of form factor for a device that has sold upwards of two billion units (a figure that’s hard to verify as Apple doesn’t disclose sales figures), and while folding screens are a pretty technology at this point, Apple’s engineers and technicians are pretty much second to none, so any hardware-related issues feel extremely unlikely. At nearly $2,000 for the base model, rising to $3,199 for the 2TB model, this is the flagship phone to end all flagship phones.

Ternus began the presentation after extolling the extensive abilities of the iPhone 18 Pro, more of which later acknowledging that we all consider smartphones to be our ‘intelligent portable hubs’. ‘A larger display would open up entirely new possibilities,’ he continued, explaining how Apple didn’t want its foldables to look like ‘two phones stuck together’.

Instead, Ternus described the company’s quest to create ‘a larger display that feels as natural and intuitive as iPad – we believe it’ll redefine the experience of using a foldable phone.’ Design chief Molly Anderson called the iPhone Duo ‘new but remarkably familiar – the same size as your passport’.

With its rounded corners, asymmetric shape and sized to feel right in both open and closed modes, the key thing is the proportions. ‘We designed iPhone Duo around a consistent aspect ratio that is the same across both displays,’ said Anderson.

A lot has had to change to make the experience work, both in hardware and in software. For a start, there’s a hidden facetime camera behind the main display, along with the sophisticated new hinge system which includes magnets to snap the device satisfyingly shut. When open, it’s the thinnest iPhone ever made, while the frame is made from mirror polished Titanium for strength (available in two finishes, Star White and Night Sky).

The inner screen measures 7.6 inches (80 per cent bigger than iPhone 18 Pro), while the outer display, slightly shorter and wider than a ‘regular’ phone is 5.4 inches. When closed, the operating system orientates status and navigation to the right-hand side of the screen; open it up and content scales but controls stay in the same place. All apps have been redesigned to accommodate the screen sizes, while orientations happen naturally – when open, closed, propped half open.

A lot of what the Duo can do – run two apps at once, swapping them around sharing info between them – is par for the course on rival folding screen phones, but don’t forget this is Apple’s first swing at the form factor. You can be sure that a lot of these transitions will be a lot smoother and more intuitive than the occasionally hacked-together feel of Android-based systems. It’s all very sleek, from the alarm clock mode to the animation that expands the outer image onto the inner screen.

Apple Pencil compatibility is also coming, the first time the iPad accessory has been applied to the iPhone. The twin batteries provide up to 31 hours of video watching on the larger inner display, while the new flagship doesn’t scrimp on camera quality, with the same camera unit as iPhone 18 Pro. Helpful features like Duo Preview allow subjects to preview their own photograph on the outer screen as it’s being taken.

It was a good thing that the Duo was saved to last, because it would have made the regular hardware and software updates seem rather pedestrian. The new iPhone 18 Pro and Pro Max doubled down on the scope and power of Apple Intelligence. It’s all part of the ongoing Mexican stand-off taking place in Silicon Valley; in the ultimate scenario, the first company to blink faces ruin as everyone else swoops in and gathers up all the addicted AI users. One sign that Apple is taking AI ennui seriously is the new Apple Reference Image, all part of the substantial camera upgrade.

New image-making features include aperture control on the 48MP main camera with a physical shutter with blades thinner than a human hair. Apple Intelligence has been deployed to amp up the Photographic Style function for added texture and tone, while new Cinematic Effects can be applied to regular video in onboard ‘post’. 4K time-lapses have been added and a new set of Pro Controls have been added for greater manual control and custom controls. Apple clearly wants to take back the crown as the king of smartphone cameras.

Apple Reference Image is a new function that ‘signs’ each photo at pixel level at point of capture by creating an unalterable ‘reference’ version of every photo you take – a ‘digital negative’ – that can be used as verification after intensive editing and generative work.

Battery life is improved, with the 18 Pro offering the same durability as the ‘old’ 17 Pro Max, while 18 Pro Max has the longest battery life of any iPhone to date, 45 hours of video playback. A new A20 Pro chip sits at the heart of both phones, squeezing on even more transistors with a 6-core CPU and 7-core GPU. Visually, there’s now a smaller ‘dynamic island’ at the top of the screen, although it’s more flexible now with up to three different status indicators on screen at once. All this is powered by iOS27.

The new AirPods 5 (pre-order now, available 18 September) come with improved personalised spatialised audio and Active Noise Cancellation, offering up to 50 per cent more noise reduction than the previous generation, as well as Adaptive Audio that automatically adjusts between ANC and transparency depending on background noise. Total integration with Siri AI allows hands-free, context-rich access to info on your device and in your messages. The Live Translation feature has been updated.

Apple Watch Series 12 (pre-order now, available 18 September) includes a new chip to power a host of Audio Intelligence features, along with much more accurate fitness metrics. New features include Live Rewind, which can transcribe the last 15 seconds of audio as well as Siri Recap, coming soon, which uses the watch’s ambient listening abilities to take away, decode and summarise key points from meetings and events (very much like what standalone devices like Plaud already do, effectively ending their small window of advantage in the rampant AI device sector). Notably, Apple pointed out that Siri Recap will deliberately not be able to identify speakers or store audio.

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There’s also more customisation on watch and band – ‘it’s not just a watch, but it’s your watch’. Series 12 finishes include Space Grey, Black, White Gold and Dark Bronze, all using recycled aluminium, with tougher glass and surfaces. Polished finishes in titanium (also recycled) are available, while a Pearl White and Night Blue ceramic finish has been introduced. The new flagship Ultra 4 model (pre-order now, available 18 September) gets up to two days of battery life, better durability and even more finishes.

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Apple Watch Ultra 4, from £749, pre-order now, available 18 September

When the dust settles and the analysis, stress tests, and teardowns begin we’ll see if Apple has made a smart move waiting for folding tech to reach full maturity before throwing its hand in the ring.

Alternatively, Apple iPhone Duo could simply be a low-volume, high status flagship device that further broadens the iPhone’s global appeal.

Apple iPhone Duo starts at $1,999 for 256GB with pre-orders from October 16
Apple iPhone 18 Pro, from $1,199, Apple iPhone 18 Pro Max, from $1,299, Apple Watch Series 12, from $399, Apple Watch Ultra 4, from $799, Apple AirPods 5, from $129, Apple.com/store