iPhone Duo brings Apple into the foldable era with iOS 27
iPhone Duo gives Apple its first foldable iPhone and introduces a hardware format that required considerably more than adding a hinge to an existing handset. The device combines a 7.6-inch inner display with a compact 5.4-inch outer screen, while iOS 27 has been adapted around the different positions, orientations, and multitasking possibilities created by the folding design.
Apple unveiled the device on September 9, positioning it above the conventional iPhone lineup with a starting price of $1,999 in the U.S. Preorders open October 16, followed by availability on October 23 in more than 70 countries and regions.
The pricing puts iPhone Duo firmly into premium-device territory, but the more significant distinction is how much of the underlying iPhone experience has been reconsidered around the larger display.

iPhone Duo turns one phone into two screen formats
When closed, iPhone Duo uses a 5.4-inch Super Retina XDR outer display intended to work much like a compact conventional smartphone. Apple says it provides more than 90% of the screen area of iPhone 18 Pro despite the smaller physical footprint.
Opening the device reveals a 7.6-inch OLED Super Retina XDR panel. The inner display is 50% larger than the screen on iPhone 18 Pro Max and uses a nano-texture finish intended to reduce reflections and make the crease less visually prominent.
Both displays support ProMotion refresh rates up to 120Hz, Always-On functionality, HDR, and peak outdoor brightness of 3,000 nits. Apple has also retained the same display aspect ratio between the inner and outer screens, allowing interfaces and content to resize proportionally when the phone is opened or closed.
The design results in some unusual dimensions for an iPhone. Duo measures 5.2mm thick when open and 11.3mm when folded, with a weight of 254 grams. Its frame and hinge cover use grade 5 titanium, while Ceramic Shield 2 protects the outer display, while Ceramic Shield covers the back of the device. The device carries an IP68 water- and dust-resistance rating.
Touch ID is built into the side button rather than relying solely on Face ID, giving users a consistent authentication point regardless of how the phone is positioned.
iPhone Duo makes iOS 27 part of the folding design
iPhone Duo would have limited value as a larger iPhone if applications simply stretched across the inner screen. Apple instead adapted iOS 27 to treat the additional space as a new working area.
Split View brings two applications side by side on an iPhone for the first time. Users can also open two windows from the same app, save pairs of applications for repeated use, and switch between tasks without collapsing everything back into a single full-screen view.
Interface elements have moved as well. Navigation controls, Lock Screen elements, and the Dock can appear along the side of the display to preserve vertical space, while Dynamic Island has been reworked for both screens. When the device is open, the Home Screen can display two pages alongside Today View.
Several physical positions have their own uses. The phone can sit partially folded on a surface for video playback, FaceTime calls, workouts, photography, or StandBy. Apple has also confirmed future support for Apple Pencil with USB-C on either display, extending the inner panel toward note-taking, markup, and sketching.
Third-party developers will determine how useful that larger canvas becomes over time. Netflix, Zoom, and Slack are among the companies already adapting their apps for the folding interface.

A20 Pro and dual batteries address foldable compromises
Foldable phones create difficult thermal and battery constraints because internal space is divided across two halves. Apple’s response is a custom hardware layout centered on A20 Pro, the same chip used in the iPhone 18 Pro family.
The 2-nanometer processor combines a six-core CPU, seven-core GPU, and dual 16-core Neural Engine. Apple says the chip can deliver up to 35% better sustained performance than iPhone 17 Pro when paired with Duo’s vapor-chamber cooling system.
A custom package connects A20 Pro directly to the vapor chamber, an arrangement designed to manage heat during gaming, AI processing, and prolonged multitasking on the larger display.
Battery capacity is similarly divided. iPhone Duo places a high-energy-density battery in each half of the enclosure and manages them as a single power system. Apple rates the phone for up to 31 hours of video playback using the inner display or up to 44 hours on the outer screen. With both displays used equally, the company estimates up to 24 hours of use per charge.
Wired fast charging can reach 50% in about 20 minutes, while MagSafe or Qi2 wireless charging can reach the same level in approximately 30 minutes.
The worldwide eSIM-only design also frees internal volume for battery capacity. Connectivity includes Apple’s N1 wireless chip with Wi-Fi 7, Bluetooth 6, and Thread, alongside the C2 cellular modem.Cameras use the iPhone Duo displays in new ways
Cameras use the iPhone Duo displays in new ways
The camera system consists of a 48MP Fusion Main camera and 48MP Fusion Ultra Wide. The main sensor also provides an optical-quality 2x option, while video recording reaches 4K Dolby Vision at up to 120 frames per second on the primary camera.
The folding design also gives the cameras capabilities that go beyond their conventional specifications. Users can shoot a selfie with the rear cameras while framing themselves on the outer display, while Duo Preview lets a subject see the live composition from the opposite side of the phone.
Smart Take uses on-device models running on A20 Pro to recognize when people appear ready for a group photo and automatically capture the image. Kid Cue can display Peanuts animations on the outer screen to attract a child’s attention toward the camera.
An under-display FaceTime camera sits beneath the inner panel, while the outer screen uses a 12MP Center Stage camera. Duo FaceTime can also place another participant on the outer display when people are gathered around the device.
Siri AI brings personal-context understanding and onscreen awareness to iOS 27, while the broader Apple Intelligence experience includes new photo-editing tools and other capabilities across apps. On the inner display, users can keep a Siri conversation visible alongside another app.
iPhone Duo will ship in Night Sky and Star White with 256GB, 512GB, 1TB, and 2TB storage options. iPhone Duo will ship with iOS 27.1 when it becomes available on October 23, while Apple says USB-C Apple Pencil support will arrive later in the year.

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