Quick answer: iPhone Duo is Apple’s first foldable iPhone. It has a 5.4-inch outer display for a compact, one-hand experience and a 7.6-inch inner display when opened. The biggest day-to-day change is not simply a larger screen: in landscape, supported apps can sit side by side. This guide covers setup and checks you can do on your own device; it is not a hands-on review.
What is iPhone Duo?
Apple announced iPhone Duo on September 9, 2026, and says it became available on October 23. It is a foldable iPhone that opens to a 7.6-inch inner display and closes to a 5.4-inch outer display. Apple’s technical specifications list a weight of 254 grams. Those numbers give you a more concrete starting point than the word “foldable”: it is a larger working canvas, but it is also a substantial device to hold.
The two displays are meant to make the phone useful in two different situations. Use the outer screen for quick checks and one-handed tasks. Open the phone when reading, comparing information, reviewing photos, or using two supported apps at once. Apps may lay out differently on the inner screen, so check the tools you rely on rather than assuming every app will use the extra space the same way.
Set up a new iPhone Duo without rushing the transfer
- Update and charge your old iPhone first. Apple recommends bringing the current device up to date before Quick Start. Choose a time when you can leave both phones nearby and connected to power; a large transfer may take a while.
- Use Quick Start or a backup. For Quick Start, turn on Wi-Fi and Bluetooth on the old iPhone, unlock it, and place it near iPhone Duo. Follow the prompts, connect the new phone to Wi-Fi or cellular, then choose whether to download from iCloud or transfer directly. Keep both devices close and powered until the transfer finishes.
- Check your cellular plan before wiping the old phone. If your number uses eSIM, the transfer depends on carrier support and your country or region. Follow the setup prompts or your carrier’s instructions, then make a test call and confirm mobile data works. Keep the old device available until the new line is active.
- Verify important sign-ins and recovery. Open your email, banking, work, and messaging apps. Confirm that authenticator codes and account-recovery options are available on the new phone. If you use passkeys, check which password manager stores them and test a second sign-in route before trading in or erasing your old device. Our iPhone passkey recovery guide explains what to check.
- Test both screens with your everyday apps. Try the apps you use most while the phone is closed and open. Check text size, buttons near the edges, video framing, and whether a layout changes when you rotate the device.
How to use Split View on iPhone Duo
Apple’s iPhone guide says Split View works when iPhone Duo is open in landscape. It lets you view two different apps—or two windows from one supported app—at the same time. For example, you might keep a message beside a photo, or view a document while writing notes. The actual usefulness depends on whether the apps you want to pair support the layout.
- Open the first app and rotate iPhone Duo to landscape.
- Swipe up from the bottom edge and pause in the middle of the screen.
- Drag the app toward the left or right side, then choose a second app from the Home Screen or App Library.
- To start another way, touch and hold an app icon and choose Open in Split View, then select the other app.
- Tap the divider between the apps to pair them. Apple says the pair can open together the next time you open either app.
Try combinations that solve a real task: Calendar beside Mail when scheduling, Files beside Notes when reviewing a document, or Maps beside Messages when coordinating a meeting point. If a particular app does not appear as an option or looks cramped, use it full screen instead; not every app has the same support or layout.
Check eSIM and Dual SIM support in your region
Cellular setup is one area where a global guide should not promise the same steps everywhere. Apple’s eSIM instructions say carrier support and the country or region matter. Apple specifically notes that iPhone Duo supports eSIM in China mainland; for Hong Kong and Macao, certain iPhone models use two nano-SIM cards. Check Apple’s current guidance for the exact model sold in your market and confirm your carrier supports the setup you need.
If you plan to use a home number and a travel line, get the travel provider’s activation instructions before departure. Do not erase the old SIM or phone until the new line can place calls, receive any verification messages you need, and connect to mobile data. For a trip, also check roaming charges and whether your main line should remain enabled.
What to test before deciding iPhone Duo is right for you
- Comfort when open and closed: hold it in both positions for a few minutes, and check whether the 254-gram weight feels comfortable for reading or video calls.
- Your actual app mix: test the apps you use for work, travel, reading, photos, and messaging. A wide screen helps most when the app’s controls make good use of it.
- One-hand tasks: try unlocking, replying, and taking a quick photo with the outer screen. A foldable can still be inconvenient if simple tasks require opening it.
- Split View habits: choose two app pairs you would genuinely use. If you rarely need them together, the larger display may matter more for reading or media than multitasking.
- Local price and support: compare the current price, storage tier, carrier terms, warranty, and repair coverage in your market. These details vary; check the listing for the exact model before buying.
iPhone Duo questions people ask
Is iPhone Duo Apple’s first foldable iPhone?
Yes. Apple describes iPhone Duo as its first foldable iPhone. It launched on October 23, 2026.
How big is the iPhone Duo screen?
Apple lists a 5.4-inch outer display and a 7.6-inch inner display, measured diagonally.
Can iPhone Duo show two apps at once?
Yes. Apple documents Split View for landscape use when the phone is open. App support and the available controls can vary, so check the apps you plan to use.
Can I transfer my old iPhone to iPhone Duo?
Apple’s Quick Start process can transfer data from a nearby iPhone. Keep both phones updated, connected, close together, and powered until the transfer finishes. You can also choose an iCloud or computer backup.
Does iPhone Duo support eSIM everywhere?
Do not assume that every model and carrier has the same setup. Apple’s support guidance is region-specific; check the page for your country and confirm with your carrier before switching phones.
Is iPhone Duo worth buying?
It is most compelling if you want a phone that can open into a larger screen and you have everyday tasks that benefit from that space. Try your own apps, both display positions, and the weight in person where possible. The feature list alone cannot tell you whether the size and foldable format suit your routine.