iPhone Duo is Apple’s first foldable iPhone, with a smaller 5.1-inch passport-style outer screen and a big 7.6-inch inner screen that mimics an iPad mini.
While the device looks amazing and the folding-unfolding software animation is chef’s kiss, there are still some solid reasons to skip this phone.
In this guide, I walk you through more than 18 reasons, drawbacks, and missing features that may make you reconsider buying this otherwise exciting new device.
Usability issues
While not a deal breaker for everyone, many people, especially those with smaller hands or who are left-handed, have raised concerns.
First, people wonder whether the wider size fits all pant pockets comfortably. Then there is the question of faster texting on the smaller outer and split inner keyboards. Some even have reservations about how to attach it to car phone holders, tripods, gimbals, mounts, etc. People who don’t always use earphones or the on-device loudspeaker are wondering how uncomfortable it will be to hold a wider phone to their ears for long calls.
Then there are left-handed people who may not be able to use the outer display comfortably, as the dock and status icons always sit on the right edge. And since those icons line up with the fixed circular camera, Apple may not spoil the look by giving the option in software to move those icons and the dock to the left side.
If you also have the above confusion, I recommend waiting a couple of months for unbiased user reviews and third-party accessories to flood the market. Then you can make an informed decision.
App compatibility
Just because iPhone Duo has two screens does not mean all your apps will work perfectly.
While popular apps should be upgraded sooner or later to fit perfectly on both the outer and inner displays, many apps that you love or use every day (especially government apps or those by small developers with fewer resources) may not be able to take full advantage of these unique display sizes unless they are updated.
This is similar to how many apps just don’t run well on iPad and appear in a small iPhone-sized vertical window. iPhone Duo will have the same problem unless apps are updated to support it properly.
First-generation product may have issues
Most first-generation products, whether they are phones, wearables, cars, or software, usually have issues that were not caught during development and the initial production phase. iPhone Duo will not be an exception!
Screen crease is still there
While Apple spent time during its keynote saying they took steps to minimize crease visibility, independent photos from people who attended the event clearly show a crease in the middle.
The matte-finish nano-texture display and excellent software implementation do a good job of hiding it, but don’t expect the crease to be magically non-existent. Plus, it’s only going to get worse as you fold and unfold the screen dozens of times daily.
Search for ‘iPhone Duo crease’ on X to see more photos.
No Action button
iPhone Duo keeps the Camera Control switch but drops the Action button. If you’re used to using this button to trigger quick actions, then you’re sure to miss it on the most expensive model.
Poorer front and rear cameras
Just like last year’s slim iPhone Air (read: 10 features missing on the iPhone Air), which had a weaker camera system than the iPhone 17 Pro, this year’s iPhone Duo follows a similar trade-off.
Unlike Pro iPhones, which have three rear cameras, the foldable sibling has just two. Reports say the main rear camera is the same as the cheaper iPhone 17e (not even the regular 17, let alone the Pro version).
On top of that, the front camera on the outer display is still inferior to those on the iPhone 17 and 18 series. It takes photos at 12 megapixels at f/2.2 instead of 18 megapixels at f/1.9.
Then the under-display camera on the inner screen has poor photo and video quality even in bright light. This’s a limitation of all under-display cameras, which is why Samsung moved away from them and replaced them with a small punch-hole camera.
Here’s a list of everything related to the iPhone Duo camera that makes it inferior to iPhone 18 Pro (and some older models):
- No telephoto lens
- 12MP front camera compared to 18MP on iPhone 18 Pro
- No Smart Focus tracking on the front camera
- No variable aperture (ƒ/1.48, ƒ/1.8, ƒ/2.8, ƒ/4.0) camera like the new iPhone 18 Pro
- No Pro camera controls for lens aperture, shutter speed, white balance, or viewing the histogram during photography and videography
- Only up to 2x optical zoom option, compared to up to 8x on iPhone 18 Pro
- Poorer optical image stabilization
- Normal True Tone flash compared to Adaptive True Tone flash on iPhone 18 Pro
- You can’t take Spatial photos and videos
- You can’t take ProRAW photos
- You can’t record ProRes or ProRes RAW videos
- No Apple Log 2 video recording
- No Academy Color Encoding System
- No Genlock support that’s enabled by compatible third-party hardware and software
No original photo watermark feature
The widespread availability of excellent AI image generation tools has led to a world where many images are fake and indistinguishable from real ones. Apple attempts to solve this by watermarking original images taken on iPhone 18 Pro at the pixel level, which tells you if the image is real or retouched by AI. This is called Apple Reference Image mode, and it’s not available on iPhone Duo.
Inferior microphone
The studio-quality four-mic array found on iPhone 16 Pro and later is missing on iPhone Duo. So expect a downgrade in video audio quality.
No Face ID and LiDAR
iPhone Duo has Touch ID in place of Face ID. Now, depending on who you ask, this can be great or a downgrade (Face ID is more secure than Touch ID; Apple said it themselves when they introduced iPhone X a decade back).
Secondly, the foldable iPhone lacks a LiDAR sensor, so it misses out on some of its depth-sensing benefits. This can result in less precise measurements in apps such as Measure, and it limits compatibility with apps and features that specifically require LiDAR. LiDAR also assists with camera autofocus in certain situations, particularly in low light, and its absence may lead to poorer overall autofocus performance.
Less battery life compared to 18 Pro Max
Apple claims the dual battery inside the iPhone Duo ensures all-day use. But overall usage is lower than the iPhone 18 Pro Max, even when you use only the smaller outer display and not the massive unfolded screen.
Apple says you can stream up to 40 hours of video on the iPhone 18 Pro Max. In contrast, this number is 37 hours for iPhone Duo on the outer display and 26 hours on the inner display.
Does not support current MagSafe wallets
iPhone Duo supports MagSafe chargers, holders, and other magnetic accessories. However, given its size, the official MagSafe wallet is unsupported. Plus, when folded, iPhone Duo is the thickest iPhone ever, and adding a MagSafe wallet on top of that is sure to make it inconvenient to carry and keep in pockets.
Less sharp inner display
While the outer display on iPhone Duo has 460 ppi of pixel density, similar to iPhone 18 Pros, the inner display is lower at 430 ppi.
Heaviest and widest iPhone
iPhone Duo weighs 254 grams and is 3.31 inches (or 84.1 mm) wide in closed mode. The iPhone 18 Pro Max is a tad lighter at 249 grams and significantly narrower at 2.83 inches (or 71.9 mm), making it more manageable one-handed.
In comparison, the Google Pixel 11 Pro Fold has bigger outer (6.5 inches) and inner (8 inches) displays, and still weighs (239 grams) less than the iPhone Duo.
eSIM only worldwide
Like last year’s thin iPhone Air, the new foldable iPhone Duo is eSIM-only in all countries where it’s sold. This can be a bummer for some who prefer physical SIMs for easy phone switching and fewer technical complications (after all, nobody likes contacting their cellular carrier for SIM issues).
Can’t play two videos at the same time
You can multitask on iPhone Duo by opening two apps on the big inner display. However, like the iPad but unlike Mac, you cannot play more than one video or livestream at the same time.
No Apple Pencil Pro support
Both the outer and inner screens of iPhone Duo will support Apple Pencil (USB-C), but it won’t support the Apple Pencil Pro, which has more features like pressure sensitivity and barrel roll.
This is because the Apple Pencil Pro only charges magnetically, and unlike the iPad, iPhone Duo doesn’t have a charging hardware strip on its side. So, if the user doesn’t already have an iPad Air (M2 or later), iPad Pro (M4 or later), or iPad mini (A17 Pro), then there is no way to charge the Pencil Pro, which may have been the rationale behind not allowing this stylus model to work on the foldable iPhone.
Another reason Apple might not allow Pencil Pro is to discourage people from pressing harder on the foldable inner screen to get a thicker pen stroke when drawing. Hopefully, iPhone Duo 2 will address this and support Pencil Pro.
Does not support Adjustable Voltage Supply charging
The iPhone 18 Pro and Pro Max support faster wired charging with USB Power Delivery 3.1’s Adjustable Voltage Supply (AVS), which lets them negotiate voltage more precisely with a supported AVS adapter for more efficient power delivery. This faster and smarter AVS charging capability is not available on the iPhone Duo.
Breaches the $2000 price tag
The iPhone X was the first iPhone to break the $1,000 price barrier. Now, the new iPhone Duo starts at a staggering $1,999, with just 256 GB of base storage. After fees, the price easily crosses the $2,000 mark, which is an eye-opening sign of just how far things have escalated in the tech world.
What are your thoughts on iPhone Duo? Are you leaning towards buying it? Or are the hefty price tag and the above compromises a deal-breaker for you?