18 features missing on the new foldable iPhone Duo
Apple's first foldable iPhone, the iPhone Duo, pairs a compact 5.1-inch passport-style outer display with a massive 7.6-inch inner screen that rivals the iPad mini. The hardware looks stunning and the folding-unfolding animation is smooth, but serious compromises lurk beneath the surface. Here's why you may want to hold off on this $1,999 purchase.
Usability Concerns with the Wider Design
The iPhone Duo measures 84.1mm wide when closed, which raises questions about pocket fit for many users. People with smaller hands or those who are left-handed face the biggest challenges with this form factor.
Left-handed users may struggle with the outer display since the dock and status icons always sit on the right edge. Apple likely won't offer a software option to move those icons because they align with the fixed circular camera lens, so lefties are stuck with an awkward reach.
Car phone holders, tripods, gimbals, and other mounts may not accommodate the wider frame without third-party adaptations. Holding the phone to your ear for long calls without earphones or speakerphone could also become uncomfortable given the expanded width.
The split inner keyboard and compact outer keyboard both present faster-texting challenges compared to standard iPhone layouts. If you have any of these concerns, waiting a couple of months for unbiased user reviews and third-party accessories is the smart move.
App Compatibility Gaps
Having two screens doesn't guarantee every app will work flawlessly on the iPhone Duo. Popular apps should eventually be updated to fit both display sizes, but smaller developers and government apps may lag behind.
This mirrors the long-standing iPad problem where many apps appear in a small iPhone-sized vertical window instead of utilizing the full screen. Unless developers specifically update for the iPhone Duo's unique dimensions, you'll see similar letterboxing and wasted space.
First-Generation Product Risks
First-generation products across phones, wearables, cars, and software typically ship with issues that surface only after widespread consumer use. The iPhone Duo will almost certainly follow this pattern.
The screen crease remains visible despite Apple's claims of minimizing it during the keynote. Independent photos from event attendees clearly show a crease in the middle of the display, and the matte-finish nano-texture coating only helps hide it rather than eliminate it.
Daily folding and unfolding dozens of times will likely worsen the crease over time. Search for "iPhone Duo crease" on X to see real-world evidence from launch events.
Missing Action Button and Biometric Changes
The iPhone Duo keeps the Camera Control switch but drops the Action button entirely. If you rely on the Action button for quick shortcuts and custom triggers, you'll miss it on Apple's most expensive model.
Face ID is also absent, replaced by Touch ID. Apple itself stated a decade ago at the iPhone X launch that Face ID is more secure than Touch ID, making this a genuine security downgrade on a flagship device.
Significant Camera Downgrades
The iPhone Duo follows the same trade-off pattern as last year's slim iPhone Air, offering a weaker camera system than the Pro lineup. Instead of three rear cameras like the iPhone 18 Pro, the foldable has just two, and the main rear camera matches the cheaper iPhone 17e rather than the standard 17 or Pro models.
The front camera on the outer display is 12MP at f/2.2, compared to 18MP at f/1.9 on the iPhone 17 and 18 series. The under-display camera on the inner screen delivers poor photo and video quality even in bright light — a limitation that pushed Samsung to abandon under-display cameras in favor of punch-hole designs.
Here is the full list of camera features missing on the iPhone Duo compared to the iPhone 18 Pro:
• No telephoto lens
• 12MP front camera versus 18MP
• No Smart Focus tracking on the front camera
• No variable aperture (ƒ/1.48, ƒ/1.8, ƒ/2.8, ƒ/4.0)
• No Pro camera controls for aperture, shutter speed, white balance, or histogram
• Only 2x optical zoom versus 8x on the Pro
• Poorer optical image stabilization
• Normal True Tone flash instead of Adaptive True Tone flash
• No Spatial photo or video capture
• No ProRAW photos
• No ProRes or ProRes RAW video recording
• No Apple Log 2 video
• No Academy Color Encoding System
• No Genlock support for third-party hardware and software
No Photo Watermark or Studio Microphone
Apple's Reference Image mode, which watermarks original photos at the pixel level to distinguish real images from AI-generated fakes, is exclusive to the iPhone 18 Pro and unavailable on the iPhone Duo. This matters in an era where AI image tools make fake content increasingly indistinguishable from reality.
The studio-quality four-microphone array found on iPhone 16 Pro and later is also missing here. Video audio quality will take a noticeable hit compared to Pro models.
No LiDAR Sensor
The foldable iPhone Duo lacks a LiDAR sensor, which affects more than just AR experiences. Depth-sensing measurements in the Measure app become less precise, and apps that specifically require LiDAR won't be compatible.
LiDAR also assists camera autofocus in low-light situations, so its absence may lead to poorer autofocus performance in dim environments.
Battery Life Falls Short of Pro Max
Apple claims the dual battery inside the iPhone Duo provides all-day usage, but the numbers tell a different story. Video streaming lasts up to 40 hours on the iPhone 18 Pro Max, while the iPhone Duo manages only 37 hours on the outer display and 26 hours on the inner display.
Even when using just the smaller outer screen, total battery life is lower than the iPhone 18 Pro Max. The unfolded inner display consumes significantly more power.
MagSafe and Charging Limitations
The iPhone Duo supports MagSafe chargers and magnetic accessories, but the official MagSafe wallet is unsupported due to the device's size. When folded, the iPhone Duo becomes the thickest iPhone ever, and adding a wallet on top makes it impractical for pocket carry.
Wired charging is also capped below the Pro models. The iPhone 18 Pro and Pro Max support USB Power Delivery 3.1's Adjustable Voltage Supply (AVS) for faster, more efficient charging, but this capability is missing on the iPhone Duo.
Display and Physical Dimensions
The outer display offers 460 ppi pixel density, matching the iPhone 18 Pros, but the inner display drops to 430 ppi, making it slightly less sharp. This difference is noticeable when reading text or viewing detailed content on the larger screen.
The iPhone Duo weighs 254 grams, making it the heaviest iPhone ever — heavier than the iPhone 18 Pro Max at 249 grams. It's also significantly wider at 84.1mm compared to 71.9mm on the Pro Max, making one-handed use much more difficult.
For context, the Google Pixel 11 Pro Fold has a larger 6.5-inch outer display and 8-inch inner display while weighing less at 239 grams.
eSIM-Only Worldwide
Like the thin iPhone Air, the iPhone Duo is eSIM-only in every country where it's sold. Users who prefer physical SIM cards for easy phone switching or who want to avoid carrier-related technical issues will find this frustrating.
Software Limitations
The iPhone Duo allows multitasking with two apps on the inner display, but you cannot play more than one video or livestream simultaneously — same as the iPad, but unlike the Mac.
The device supports the Apple Pencil (USB-C) but not the Apple Pencil Pro, which offers pressure sensitivity and barrel roll. The Pencil Pro charges only magnetically, and the iPhone Duo lacks the charging hardware strip found on iPads, making it impossible to charge the stylus without a separate compatible iPad.
Apple may also be intentionally discouraging users from pressing harder on the foldable inner screen for thicker pen strokes, which could damage the display. The hope is that the iPhone Duo 2 will address this limitation.
The Price Problem
The iPhone X was the first iPhone to break the $1,000 price barrier. Now the iPhone Duo starts at $1,999 with just 256GB of base storage, and after fees, the price easily exceeds $2,000.
Given the camera downgrades, missing Face ID, no LiDAR, shorter battery life, absent Action button, no Pencil Pro support, and limited app compatibility, the iPhone Duo asks a premium price for a first-generation product with substantial compromises. Waiting for user reviews and the inevitable iPhone Duo 2 refinements may be the wiser choice.