Let's just come out and say it. The iPhone Duo is maybe the most interesting Apple product in years because it's one of the riskiest. It's a huge rethink of what an iPhone is and could be. It's made me reconsider exactly how I'm supposed to use a phone, and it contains the seeds of a lot of fascinating ideas that might be great in the future. It is also one of the messiest first-generation products Apple has released in a long time, and it's incredibly expensive. Prices start at $2,000 for 256 gigs of storage and go up to $3,200 for the two-terabyte model. The iPhone Duo is a lot of things, but right now the most important thing is that it's a long way from being ready for anyone but gadget nerds and early adopters. That's great, because I'm a huge gadget nerd and I had a ton of fun doing this review with our senior reviewer, Allison Johnson. And we have an awful lot to say about the iPhone Duo.
It's been a minute since the iPhone has looked or worked in significantly new or different ways. The last major change was the iPhone X, which dropped the home button almost a decade ago, and even that was a fairly subtle improvement. Subtle improvement is really the entire story of the iPhone. It's the foundation of Apple's entire business, after all, and there's a lot of risk in just up and changing it. You can see Apple's tendency to play it safe in this year's iPhone 18 Pro, actually. It's been refined in many ways, and it has better thermals and an interesting variable-aperture lens, but on the whole it's barely different than the iPhone 17 Pro. You can't play it safe designing a foldable. There's just no way to do it. You have to make some big decisions about screen sizes and what the inner and outer displays are for, and then make an even bigger set of decisions about how the inner screen should work. All of those decisions are inherently risky. And so Apple's riskiest decision was the Duo's passport size and shape, which the rest of the industry copied before the Duo was even announced.
Everything about the Duo really comes back to the shape and how it balances the usefulness of the inner and outer screens. The Duo's outer 5.4-inch display is glossy, while the inner 7.6-inch display has a nano-texture matte finish that's really quite striking. Apple is very proud of this inner matte display, and for good reason. So what's crazy is it's the matte screen, but it looks like a sticker you should peel off. It looks and feels incredibly solid. A big step up from other foldables with glossy, seemingly soft screens with glaringly obvious creases like the Pixel Fold, and even the more subtle but still visible crease of the Galaxy Fold8. That matte display is actually there to help hide the display crease, which Apple keeps calling "perceptually flat" because it's more fun to invent sciencey marketing phrases than to just say you mostly don't see it. But it's true: you mostly don't see the display crease, although you can definitely feel it, and it's not totally invisible. If you're looking at a white image off-axis, you can see it. There are moments in some lighting where it's obvious, and it definitely shows up on camera like this more prominently than it does to your eyes. What you will see is the under-display FaceTime camera, which definitely reflects light in a more glossy way if you're outdoors or in a bright area. None of this was the end of the world, and I never found the camera or display crease distracting. It all just faded into the background after a week of constant flipping and folding. Of course, we'll have to see how this all holds up over time. But let me tell you, Duo owners are going to be constantly flipping and folding this thing.
Between Apple's choice of hardware display aspect ratios and iOS software design choices, the outer display feels like much more of a status display than you'd expect. Everything about the Duo gently nudges you to flip it open and use it in tablet mode — and not just tablet mode, portrait tablet mode. You need sure hands to really get into the zone with a Duo. This is a phone you're going to figure out moves for. Here's what I mean. iPhones have only gotten bigger over the years, but they've mostly stuck to the same basic rectangular aspect ratios: 2 by 3 from the first iPhone through the 4S, 9 by 16 from the iPhone 5 through the 8, and 9 by 19.5 from the iPhone X onto today's iPhone 18s. Basically, the iPhone has mostly gotten taller over time. The Duo changes all that. It's the first iPhone that's gotten shorter and wider. Both the inner and outer displays have a 1.4 to 1 aspect ratio, which was a very deliberate choice on Apple's part. It means they're the same shape open and closed. This is very clever in terms of display math and app support, but it also means the outer display is really quite small, especially compared to modern Max-sized phones. Apps that haven't been updated for the Duo just look tiny on this display, with a black bar on the side. And you'll be seeing that black bar a lot, since most apps haven't been updated yet. It's very much like having an iPhone 5 in a Pro Max world.
Now, Apple's tried to reclaim some vertical space by scooting the interface elements of updated apps off to the right, but if you're left-handed like me, that means using the phone closed with one hand can be challenging. I have big hands and I can do it, but it's still a stretch, and I have to basically balance the phone in my hand instead of holding it securely. It's also kind of wild to have iPhone apps with controls in all kinds of different places. A lot of using the Duo is just thinking about how to use an iPhone again, which hasn't happened in a long time. Even updated apps don't feel particularly useful for anything other than a quick check-in on the outer display. Apple says you're getting 90% of the screen area of an iPhone 18 Pro, which is pretty small for today's apps. If you're texting someone in Messages with a keyboard on screen, you're lucky to be able to see two or three texts at once. So when you pull the Duo out of your pocket, you'll almost always be looking at a tiny amount of information. And the second you want to really do anything, you'll find yourself unfolding the phone to use the vastly larger and more useful inner display. In some ways, this really makes you use the phone less. It's just not as easy to get sucked into the outer display because it's so small, and using the inner display feels like more of a production that requires two hands. I just spent less time oddly scrolling Instagram and TikTok on the Duo than on my regular phone. It doesn't seem made for that, but that clever matched aspect ratio means the Duo opens to landscape, and going from a tiny portrait display to a bigger landscape just isn't useful for most phone apps, which are all designed around big portrait displays.
Apps that are still running as standard iPhone apps, like TikTok, look pretty silly this way. It's cramped and tiny on the outer display and, well, just look at it when you open the Duo. This means every time you open the Duo, you instinctively rotate it. And while it will work no matter which way it's rotated, it's worth noting that it's better to rotate it counterclockwise. So you end up with the cameras on top and the volume buttons on the top left. Over a week of testing, I got used to this, but it's exactly the opposite of what you'd expect, especially in Apple's bumper case, which has a notch for the Touch ID and camera buttons that looks for all the world like it should be at the bottom. I keep holding it upside down. I realize this all sounds like a little thing, but it is wild to find yourself unsure of how to hold a smartphone, especially because the Duo doesn't have Face ID, which means you'll be reaching for that Touch ID sensor quite a lot. A hilarious Duo hack is just registering as many fingers as you can for Touch ID so you can just hit the sensor however you're holding it. I have both index fingers and both thumbs set up, and I know at least one important person with their pinky registered as well. This kind of thing comes up a lot with the Duo. A non-trivial part of the Duo experience is just looking to see where the volume buttons are as you flip the thing around. Closed, they're on top of the phone, but if you do happen to rotate the Duo clockwise, they end up on the bottom right, and by default it's the top button that turns the volume down, because they don't change orientation with the display. Side note: there's actually a buried setting in iOS that makes the volume buttons reorient themselves as you turn the Duo around. Bizarrely, you have to turn it off, which is very confusing. Apple really needs to set it so it works correctly by default.
If I have two main design notes about the Duo, it's that it needs to be a little bit bigger so that the outer screen is more useful, and that Apple just needs to get over it and make all of these buttons bigger and easier to see. Minimalism is delightful and all, but I would really rather know where the volume buttons are. The Duo's size also makes using it as a phone much more surprising than you'd think. It's so much smaller than modern phones and just feels cute against your ear. And in tablet mode, it only works as a speakerphone, which is fine unless you had a bunch of fun ideas for gags in the review video. Let me just take a beat here and say this clearly: I thought all this was pretty fun. The iPhone has been the same for so long that being forced to come up with little moves and tricks and ways to think about holding the Duo hit the gadget nerd part of my brain in the best possible way. Other foldables do this too. Samsung and Google and Huawei have been pushing the envelope of gadgety smartphones for ages, but Apple's played it so safe for so long that the Duo is legitimately surprising. Like I keep saying, it's messy in a way that I think most people will find a little frustrating, but early adopters might actually enjoy.
That first-generation messiness is most obvious when it comes to the software, which is basically all over the place, especially in how the Duo supports third-party apps. Apple could have gone the easy route here and just made this thing an iPad when you open it, but in classic Apple fashion, it decided to throw everything out and start over. That means getting rid of a lot of weird iPad baggage for sure, but it also means solved problems in the iPad are back on the Duo. It's big stuff and little stuff. For whatever reason, the Duo doesn't support pinching the keyboard to make it smaller and friendlier to use one-handed, a feature iPads have had for ages. I ended up using my nose to poke around on the screen and type one-handed with a Duo in tablet mode quite a bit. Between the Duo and the watch, Apple has quietly revolutionized nose typing. It also means there are entirely new ways to think about multitasking. Sometimes you're going to end up totally unsure about what will happen when you swipe around on the screen, as all these apps interact with iOS and each other in very different ways. If you want to run two apps at once on the Duo, you swipe up and over to pin an app to one side, and then pin an app to the other side. If you tap a little divider, you connect the apps into a set, and you can come right back to it in the app switcher. It's neat, but it only works in landscape. You want to have two apps open when you're holding the Duo in portrait, and you're basically out of luck, unless what you want is to watch a video on the top while scrolling an app on the bottom. In that case, you need to make sure you have an app that supports background video, open that app, start the video, close the app, and then find this little button in the floating video window and hit that. This is legitimately cool once you figure it out, but you will note that this is a totally novel approach to multitasking, and nothing about the Duo's interface makes it obvious that it'll work this way.
It turns out there are basically three categories of apps for the Duo right now. There are regular old iPhone apps which haven't been updated at all. They just show up as iPhone apps the same way they do on an iPad. You can zoom in and rotate them to make things a little more useful, but they look pretty silly. This is the vast majority of apps at the moment. On the other end of the spectrum, there are fully updated apps built for the Duo-specific iOS 27.1 that take full advantage of the Duo's displays. Then there's the messy middle, which are apps that have just been updated for iOS 27. They get some automatic support for tablet layouts to fill out more of the inner screen, and they don't look quite as silly as the tiny little iPhone apps, but they aren't actually designed for the Duo yet. The telltale sign of these apps is that black bar on the right side. Proper Duo apps fill that space, but these in-between apps don't. Here's the Gmail app, which has been updated for iOS 27 but not updated for the Duo. You can see it doesn't really take advantage of the larger screen size. You don't get to see your inbox and your emails at the same time. It's really just a bigger iPhone app. Here's Lightroom, which I was very excited to use on the Duo. You can see it fills the inner display, but it hasn't actually been designed to make good use of it. So the content window is tiny and the edit controls just slide over the photo you're editing. No human designer ever looked at this YouTube Shorts comments interface.
Now, apps that have been updated specifically for the Duo can be pretty great. Instagram's Edits app is a perfect example of why a folding phone is useful. It opens into a full video editor with a big timeline and a nice preview window, and you can just get things done. Flighty, the flight-tracking app, looks really great with this big map on the inner display. The Netflix app is a real standout. The developers took advantage of Duo-specific features like the hinge sensor, so the reflections change as you move the display. It's incredibly neat. It's no surprise that I love the Deck-Man app, which reformats Apple Music into a little virtual Walkman, and of course, the page turn animation in Books is terrific. That bigger screen is also great for watching video. Obviously, it works best with optimized apps like Apple TV, but the Duo's software is smart enough to zoom in on video from standard iPhone apps as well. I watched VisionQuest on the Duo in Disney+, which hasn't been updated yet, and it filled the screen nicely with nice, bright HDR highlights and decent sound from the speakers. In many ways, the fact that the Duo opens to landscape means proper landscape video might have a chance again. It's just nicer to watch on this thing than vertical video.
But I think a lot of people will expect the Duo to unfold into an iPad, with the entire ecosystem of iPad apps waiting at the ready, and that's just not what's happening here at all. You can feel the Duo bumping up against those iPad expectations a lot. It's funny — it feels like the iPhone Duo wants to be an iPad in the same way the iPad wants to be a Mac, but for whatever reason, Apple didn't go that way, so you're going to see a lot of little tiny phone apps and apps in the weird unoptimized middle zone for a while, and get yourself into objectively hilarious situations while multitasking. I often find myself needing to read and react to documents on the go, and so I was particularly excited to use the Duo to multitask with Slack or reading a PDF and editing in Google Docs, something I do dozens of times a day. I read a lot of PDFs for work, and PDFs look great on this big matte display. The Duo can handle this sort of thing, but it was all pretty messy in a lot of the same ways that Android foldables are messy. Actually, let's talk about Android foldables for a minute. Allison has been using the Duo next to the Galaxy Z Fold8, and it's surprising how different things are, even though Samsung went with the same basic passporty size.
Allison and I had pretty different battery life experiences. I tried my best to use the Duo just like I would during any other workday, in Slack, Google Docs, and Safari, and watching YouTube TV, Instagram, and TikTok, and I found myself needing to charge the Duo at least once to make it through. This matches my normal experience with my regular Pro Max iPhones, but if you're used to getting through a day, the Duo might take some adjustment. Allison traveled more with the Duo, and she spent more time watching video and social media on Wi-Fi. She reported having about 30% battery life after about six and a half hours of screen-on time, which is decent. All in all, it doesn't seem like the Duo will ever go for a full day of heavy use, but it's hard to tell, given that Duo battery life will change a lot depending on how often you open it and use the larger screen, which definitely drains the battery faster. And iPhone battery life tends to change a lot over time. I've never found any iPhone to be as solid after a year as it was in the beginning, and I'm assuming the Duo will be the same way, so we'll have to see.
Performance-wise, the Duo has an A20 Pro chip, and Apple says it has the same improved vapor chamber thermal management system as the iPhone 18 Pro. For most things, the Duo is plenty fast, but the reality is that it's also a thin phone driving two big displays. I saw this happen in two places. Third-party apps, and particularly Google's apps, cause things to get warm, sometimes hot. That's in line with the Duo being a first-generation product. You would hope that that improves as apps get updated. I was much more concerned about the phone heating up when you used the camera for a long time, especially when you use features that use the camera in both displays at once, like Duo Preview and Kid Cue. You can just feel the phone heating up when this happens. Add in processor-intensive camera features like Smart Take, which automatically hits the shutter button when it detects a good pose, and we saw the Duo get pretty hot and start noticeably lagging after a while. This phone is getting hot and it's also slowing down. Allison spent more time testing the camera, which has other compromises due to the Duo's size.
