The iPhone Duo can run two apps side-by-side on its 7.6-inch foldable display, but the split is fixed at a 50/50 divide — you cannot drag the divider to make one app larger than the other.
Apple’s marketing highlights app pairs and side-by-side windows but does not mention any ability to resize those windows. That omission mirrors the device’s behavior: placing two apps next to each other always yields an even split.
Apple likely restricts resizing because of the Duo’s display geometry. Both the inner and outer displays share a 1:1.4 aspect ratio, and each half of the inner display is roughly the same size and shape as the outer screen. An even split gives each app a canvas it already has to support, with the divider sitting neatly on the fold. Allowing an adjustable boundary would create many intermediate sizes that wouldn’t map cleanly to the outer screen and would complicate developer support.
The limitation will be conspicuous to iPad users: iPad Split View has allowed users to resize apps in landscape since 2015, when iOS 9 introduced the feature. A tweet from @planetofgori on September 10, 2026, underscored the restriction: ‘So unfortunately, you can’t change the app size when you use split view on the iPhone Duo. Only 1:1.’ (Japanese: 画面分割した際のアプリサイズは変えられない仕様です)
Why iPhone Duo fixes split view to 50/50
The Duo’s matching aspect ratios and the fold’s position make a symmetrical split the simplest way to ensure each app sees a familiar canvas that also corresponds to the outer screen. Permitting arbitrary splits would introduce sizes that don’t translate to the outer display and increase the burden on developers to support a wide range of nonstandard window dimensions.
What you can still do with the foldable display
Despite the lack of resizable Split View, the foldable screen enables several multitasking conveniences: you can quickly swap between apps, open two windows of the same app, and hold a Messages conversation on one side while viewing another app on the other side in both landscape and portrait orientations. The Duo also lets you save app pairs to reopen later.
Apple’s first iPhone with a foldable display will likely present a learning curve for users coming from the iPad. The iPhone Duo starts at $1,999; pre-orders begin Friday, October 16, and availability starts Friday, October 23.
