Apple spent most of its keynote time talking up the iPhone Duo’s two screens, its cameras, and the engineering that went into making a foldable iPhone feel like an iPhone. But once the event wrapped and Apple’s website went live, a handful of smaller details started surfacing that didn’t get a mention on stage. None of these are dealbreakers on their own, but they’re the kind of thing you’ll want to know before you place an order in October.
The cameras aren’t identical across iPhone models
iPhone Duo gets a few camera features you won’t find anywhere else in the lineup, including Smart Take, Kid Cue, and Duo Preview. That’s the good news. The catch is that the Main camera skips the variable aperture that’s on iPhone 18 Pro, so if that feature mattered to you, the Duo doesn’t carry it over.
There’s also a first for the iPhone tucked inside the fold: an under-display camera on the inner screen. It’s a neat trick for keeping that display free of a cutout, but it comes with a trade-off. That inner camera isn’t nearly as capable as the Center Stage camera on the outer display, so for FaceTime calls or selfies, you’ll still want to reach for the outside screen when you can.
No Action button
iPhone Duo has a Camera Control button, same as the rest of the current lineup, but it drops the Action button that’s been standard on iPhones for a few years now. If you’ve leaned on that button for quick shortcuts, that’s one habit you’ll need to rebuild on the Duo.
Nano-texture is only on the inside
The nano-texture finish, the anti-glare coating Apple usually reserves for its Pro displays, is only available on the folding inner screen of the Duo. The outer display doesn’t get the option at all, so if reducing glare outdoors is a priority for you, that only applies to the screen you’ll have folded away most of the time.
Apple Pencil support is limited for now
Apple confirmed Apple Pencil support is coming to both displays on the iPhone Duo, but not right away. It’s listed as arriving later this year, and even then, it’s the USB-C Apple Pencil that’s supported first. The Apple Pencil Pro isn’t compatible at launch, which is worth knowing if you were planning to use your existing Pencil Pro with the new phone.
It ships later than iPhone 18 Pro
While iPhone 18 Pro goes on sale this week, iPhone Duo is on its own schedule. Orders open on October 16, and the phone starts shipping a week after that, on October 23. If you were expecting Duo units to land alongside the rest of this year’s lineup, you’ll be waiting a bit longer.
It launches on iOS 27.1, not iOS 27
Given that late October release, it tracks that iPhone Duo won’t ship with the iOS 27 that’s rolling out this week. Apple has confirmed the Duo will launch running iOS 27.1 instead, which likely means a few Duo-specific refinements will land in that point update rather than in the initial release.
eSIM only, everywhere
iPhone Duo will not offer a physical SIM tray in any market. That includes China, where physical SIM cards remain the norm and where Apple has historically kept a SIM slot available on other models specifically for that market. The Duo breaks from that pattern entirely, so if you’re switching to this phone, plan on eSIM regardless of where you are.
Why these details matter
None of these points change what the iPhone Duo is at its core: Apple’s first real attempt at a foldable iPhone, with two displays, strong battery life, and a form factor nobody else in the lineup offers. But if you’re deciding between the Duo and the iPhone 18 Pro, these are exactly the kind of details that get buried under the bigger headlines and end up mattering once the phone is actually in your hands.
