UISupportsTrueScreenSizeOnMac
A Boolean value that indicates whether your iPad app supports arbitrary screen sizes and resolutions when running on a Mac.
Discussion
To declare support for arbitrary screen sizes and resolutions when running your iPad app in macOS, add this key to your app’s Info.plist file and set its value to true. This key has no effect when:
The app supports iPad multitasking and resizable windows. For more information, see UIRequiresFullScreen.
The app is running on other Apple platforms.
The app is built with Mac Catalyst.
The use of this key implies that your app is capable of handling a variety of display configurations available on a Mac, including:
Small to large display resolutions; for example, 640 x 480 to 8K and beyond.
Retina and non-Retina displays.
All conceivable aspect ratios, including portrait and 21:9 ultrawide.
Use of the UISupportsTrueScreenSizeOnMac key also implies that your app is capable of handling portrait and landscape sizes even when they don’t align with the device orientation. For instance, if your app supports rotation in iPadOS, the device orientation is always landscape even though the display might have a portrait aspect ratio in reality.
When you include UISupportsTrueScreenSizeOnMac in your app, your app is responsible for:
Handling memory management concerns that may occur when running at extreme resolutions.
Handling layout concerns for different aspect ratios, such as correct button placement.
Letterboxing and pillarboxing as needed if your app requires a specific aspect ratio.
To provide a pixel-perfect, edge-to-edge, full-screen experience, use UISupportsTrueScreenSizeOnMac along with the UILaunchToFullScreenByDefaultOnMac key.