Apple’s new foldable iPhone Duo introduces side-by-side multitasking for the first time on an iPhone, but it falls short of the flexible window resizing iPad users have long enjoyed. The split view on the Duo is locked into an equal 50/50 layout, and there’s no dragging of the divider to adjust how much screen real estate each app gets. This fixed split applies even though Apple is promoting the ability to run app pairs and windows side-by-side.
On an iPad in landscape mode, since iOS 9 back in 2015, users have been able to adjust the width of split view panels—letting one app take more space than the other depending on what they’re doing. That freedom doesn’t exist on the Duo. Even when the internal 7.6-inch foldable screen is open, the divider remains perfectly centered.
Why no flexible resizing?
The limitations seem linked to the geometry of the Duo’s displays. Apple’s Duo has both outer and inner screens sharing a 1:1.4 aspect ratio. When split equally in half, each app gets a display space similar to what it already supports on the outer screen. That consistency likely helps with layout predictability and developer optimization.
Allowing freeform resizing would introduce intermediate layouts that don’t translate well to the outer screen or match existing app sizes. That places more burden on developers to support irregular dimensions, which could affect app stability and user experience.
What you cando
Despite being locked into a 50/50 app division in split view, Duo still brings multitasking features not found on previous iPhones. Users can open two windows of the same app, swap between apps easily, and use app pair presets so two apps are pre-loaded side-by-side. These work in both portrait and landscape orientations.
One exception to the fixed split appears during video content in portrait orientation: when watching a TV show or movie above another app, the video is shown in its native aspect ratio, and the lower app can extend above the fold. That seems to be the only situation where the fixed split is relaxed.
To recap: although split view on the Duo enables an iPad-style multitasking mindset, it lacks the flexibility of adjustable app sizing. It’s more rigid than what longtime iPad users are used to. The Duo starts at $1,999; preorders begin October 16, and it ships October 23.
Understanding the limits of Duo’s split view feature highlights different design decisions between foldables and tablets. For users considering multitasking on an iPhone, the Duo offers real gains — two apps at once, app pairs, multiple windows — but it won’t offer full parity with the iPad’s mature freedom. Whether those trade-offs matter will depend on how much customization you want in your workspace. As developers adjust apps for the Duo, watch for creative workarounds or hidden tweaks that might restore some flexibility down the line.
