Mac-catalyst – minimum window size for Mac catalyst app

Just add the following chunk of code to your application:didFinishLaunchingWithOptions method (for UIKit projects) or to scene(_:willConnectTo:options:) (for SwiftUI projects):

UIApplication.shared.connectedScenes.compactMap { $0 as? UIWindowScene }.forEach { windowScene in
    windowScene.sizeRestrictions?.minimumSize = CGSize(width: 480, height: 640)
}

PS: you can also set the maximumSize property there

PS2: If you set both minimumSize and maximumSize to the same value, the window size will remain static and won’t be resizable.