Apple’s WWDC sessions usually offer a mix of developer guidance and subtle hardware tea leaves. And last week, one passing comment during the explanation of an SDK change caught attention for what it might suggest about a particular future device.
In a session called “Make your UIKit app more flexible,” Apple confirmed that starting with the iOS 26 SDK, apps will no longer be automatically letterboxed or scaled on new screen sizes when running on future hardware.
Historically, when Apple introduced a taller iPhone, a new iPad aspect ratio, or any other form factor shift, apps built with older SDKs would default to running in a scaled or letterboxed mode. Developers would only get true native rendering once they updated their app against the latest SDK and resubmitted it to the App Store.
With iOS 26, that behavior changes. Quoting directly from the session:
“There is another compatibility mode, specifically for new hardware. Previously, when new hardware was released with a different screen size, the system would scale or letterbox your app’s UI. That scaling would stay in place until you built with a newer SDK and resubmitted your app. Once you build and submit with the iOS 26 SDK, the system will no longer scale or letterbox your app’s UI for a new screen size. These are the best practices to ensure that your app is flexible.”
That may sound like a small technical tweak, but the timing and the specific language around “new hardware” and “new screen size” feel… notable.
As pre-iPad 9to5Mac readers will remember, Apple doesn’t typically enforce this kind of preemptive UI flexibility unless it’s gearing up for a form factor where scaled apps would look especially bad.
And given the ongoing rumors about a foldable iPhone in development, it’s hard not to read this as the clearest OS-level sign yet that bigger display changes are coming.
The aspect ratio game
Last month, Weibo leaker Digital Chat Station shared the following claim on the foldable iPhone’s aspect ratio:
“The latest version of Apple’s foldable engineering prototype has a slightly smaller screen size compared to the one previously seen, but the resolution and aspect ratio remain unchanged. The inner screen uses a 14.1:10 under-display camera technology, while the outer screen features a 14.6:10 punch-hole design. Side-mounted Touch ID fingerprint sensor.”
Modern iPhones typically have an aspect ratio of 19.5:9, with some older models using 16:9. Meanwhile, current iPads have either a 3:4 or a 16:23 aspect ratio, depending on the model.
Put simply: it looks like the foldable iPhone’s large internal display might have its own specific aspect ratio, and Apple may already be laying the groundwork to avoid any letterboxing that could hurt first impressions.
Foldable or no foldable, apps need to flex
While Apple stopped short of naming any specific device categories, the session’s focus on “future hardware” and non-standard screen sizes does line up neatly with the kind of UI challenges a foldable phone would introduce, especially in its unfolded state.
For developers, the takeaway is straightforward: If your app’s UI isn’t already ready to scale fluidly across arbitrary screen sizes, now’s the time to fix that.
For everyone else? File this under yet another small-but-interesting breadcrumb on Apple’s long road toward whatever comes next in iPhone hardware design.