The Apple iPhone Duo is the rare Apple product that has not received universally glowing or negative reviews. Opinions are split over its lack of Face ID support, iPhone 17 Pro-grade cameras (but without the telephoto lens), and slightly hefty frame when folded. It’s also generated more interest in an iPhone than I’ve seen in years, and when I followed my exhaustive, generally positive review with a pair of AMAs (Ask Me Anything) on Threads and X, I was flooded with questions. My Threads post alone has 1,300 comments.
Granted, not every question was about the Duo. Many took the “Anything” part literally and asked me about everything from my hairline to their favorite color. I played along as I fielded myriad queries about Apple’s first folding device. Over 24 hours, I reiterated many points from my review, which I doubt many read, but I also learned a thing or two I missed while testing the product.
Here are some of the highlights:
For my iPhone Duo review, I placed the folded phone on multiple MagSafe charge stands and holders. The MagSafe magnets sit on the back, right under the camera array, and the Duo fits perfectly on each stand. With charge stands, the Duo instantly slips into the redesigned Standby mode. I love it.
Someone on Threads asked me if I had tried unfolding the Duo and putting it on a MagSafe stand. So I did and quickly found that the weight of the half not attached to the charging stand made the entire phone rotate ever so slowly on the MagSafe charger. So, while you could use the unfolded Duo on a MagSafe charging stand, it is not recommended.
After someone else asked if they could still use their MagSafe Wallet, I found that the Duo’s back is too short to accommodate the standard MagSafe Wallet.
With its two differently sized screens, the iPhone Duo is unique in the iPhone lineup, and there were reasonable questions about how features like vertical Wallpaper images work across the cover and inner display.
I didn’t know, so I set the cover wallpaper as a vertical photo I took with the Duo of the Empire State Building, and I gotta say, I love the handoff between displays. The Cover display showed the iconic building, and when I opened the Duo, it showed more of the photo.
There were a lot of questions about the Duo’s split-screen capabilities, like if I could open more than two apps (no, but you can do a PiP video overlay), and if you could drag and drop content from one screen to another (you can).
Some wondered if you could run the same app on both screens. You cannot, but if you want to maximize your social media, I found that you could run TikTok and Instagram Reels in side-by-side windows. It’s social media turned up to 11.
During my review, I tried running the Kindle app, but the app wasn’t optimized for the device and looked tiny and useless. Someone asked me about “iBooks,” which is now known as Books.
As a first-party app, it’s optimized for Duo, of course. Flipping virtual pages on the 7.6-inch inner display is a transporting experience.
Many wondered whether I hated the matte finish on the inner display (I don’t), but I also got a ton of questions about the crease and the inner display’s overall durability. A few wanted to know if I’d scratched it, either purposefully or by accident, with my fingernail. I had not, honestly; I don’t even see fingerprints on the matte display.
A couple of people asked about the visibility of the crease and whether that area of the screen bounced or wobbled when I touched it. So I tested it by opening the phone and pressing down on the essentially invisible crease. No movement.
Many had obviously heard that not every app is optimized for the new inner display. In my review, I noted that LinkedIn and Gmail were particularly poor fits and later found that Adobe Acrobat still wasn’t optimized. But developers are constantly delivering updates, so apps that didn’t work yesterday look great today.
Still, people wanted to know how apps deal with the handoff from the 5.4-inch outer display to the 7.6-inch inner one. Optimized apps handle it smoothly; most simply expand without losing context.
Some, like DeckMan and Toastie, playfully use the two screens to create entertaining interplays. DeckMan, for instance, turns the duo into a virtual portable tape deck.
An almost equal number shared their concerns about the size of the 5.4-inch cover display. It’s actually not that small, but Apple’s decision to place the Dock vertically on the right-hand side means that you lose a lot of pixels to what is often empty space. Others complained about the lack of support for left-handed users (they kept asking me if I was left-handed). Some are even bothered by the dock’s placement on the much larger inner display. You can’t move it, and this will probably remain a key issue for many potential Duo owners.
Every single iPhone model now supports Face ID, with the notable exception of the new Duo. It’s probably the single biggest Duo misstep, and many asked me if I was having trouble adjusting to using Touch ID again. Initially, I was, but I have gotten used to it. I hope the next Duo brings back facial recognition.
I probably got a dozen or so questions about battery life. Some reviewers have criticized the Duo for subpar battery life if you mainly use the larger inner screen. I did not find that, but I did field quite a few battery life questions from concerned potential buyers. I told them what my tests found: all-day battery life in a variety of situations.
I struggled a bit when people asked me to compare the Duo to the iPhone 18 Pro Max. I get it; they want to know if they should stick with what they know or, perhaps, try the awesome new thing. It’s not easy, though, to directly compare the single-screen iPhone 18 Pro Max with the dual-display Duo. But leaving aside the screens, if you focus on, say, the cameras, you might stick with the 18 Pro Max, which offers a telephoto and a variable-aperture main camera. The Duo is also heavier than the iPhone 18 Pro Max, which might be a deal-breaker for some.
There were also a healthy number of comparisons to the Samsung Galaxy Z Fold 8 lineup, especially the similarly sized and shaped Galaxy Z Fold 8. A few asked me to compare the cameras. Turns out that both the Z Fold 8 and Duo have just two external cameras: wide and ultra-wide, and the Z Fold 8 has just a couple of megapixels per camera on the Duo. Ultimately, it’s a wash on the camera front.
I got just as many questions about the cameras’ quality, including the 12MP Center Stage camera on the outside and the 4MP inner camera. I found it interesting that many knew not to directly compare it to the new iPhone 18 Pro Max lenses and instead focused on the more comparable iPhone 17 Pro’s wide and ultrawide. In my testing, I found the imagery was just as good as what I got from that now year-old device. I do, however, miss the telephoto lens.
One person actually asked how this iPhone Duo is different from the Surface Duo that Microsoft launched in 2019 and discontinued in 2024. I gently explained that while the Surface Duo’s inner screen had two displays, the iPhone Duo offers one flexible inner display.
Apple hasn’t said much about Apple Pencil support, but that may be because the Duo currently only supports the Apple Pencil USB-C. Why? It’s the only one that you can still charge separately from, say, a tablet. Apple Pencil Pro needs the iPad to charge. The Duo cannot charge another device. As one Threads user put it, “Which basically means that my Pencil Pro is useless?” Mine too, my friend, mine, too.
