Mapping UWP features to the Windows App SDK

This topic compares major feature areas in the different forms in which they appear in UWP and in the Windows App SDK. The content in this migration guide supports moving from UWP XAML to Windows App SDK XAML—moving to a different UI framework, such as Windows Presentation Foundation (WPF), is outside of the scope of this guidance.

Feature	UWP	Windows App SDK (packaged apps)	Migration notes
Packaging	MSIX App has identity	MSIX App has identity	UWP apps migrating to the Windows App SDK should stay on MSIX to ensure trusted clean install and uninstall experience, as well as access to all APIs, including those that require identity.
Container	App container: - security = LowIL - file system access is brokered - no registry access	MSIX Container: - security = MediumIL - file system access same as user, AppData writes virtualized - HKCU registry writes virtualized	Moving to a higher integrity level with the Windows App SDK allows your app to have greater functionality. However, be aware of virtualization if you want to expand the capabilities of your migrated application to write to HKCU or AppData.
Activation and instancing	Package identity + CoreApplication activation, single-instanced by default	Package identity, Main/WinMain + Windows App SDK activation, multi-instanced by default	Ensure your application can handle multi-instance behavior, or use AppInstance to manage your instances.
Lifecycle-managed	Suspend/resume	Power/State notifications	You can use Power/State change notifications to reduce system load.
Background tasks	InProc and OOP background tasks	Inproc COM and OOP background tasks	You can continue to use your OOP background tasks. If the app requires communication to your main process, then evaluate your IPC mechanism, as the OOP background task is running in LowIL, and your Windows App SDK main process is running in MediumIL. Any inproc background tasks need to be migrated to COM background tasks—see Create and register a winmain COM background task. For C# OOP background tasks, see Author Windows Runtime components with C#/WinRT and the Background task sample.
Windowing	CoreWindow, AppWindow (preview)	HWND, AppWindow v2	Windowing behavior has significantly changed in Windows App SDK. See Windowing functionality migration.
Messaging	CoreDispatcher and DispatcherQueue	DispatcherQueue, WndProc	DispatcherQueue supports Win32 apps. For additional details on moving from CoreDispatcher to DispatcherQueue see Threading functionality migration.
UI Platform	System XAML, WebView, DirectX, and others	WinUI 3, Webview2, DirectX, and others	For more info, see Windows UI Library (WinUI) migration.
Text-rendering	DirectWrite	DWriteCore	Enables applications to access the latest DWrite features downlevel and receive new DWrite updates separate from the OS release schedule. For more info, see DirectWrite to DWriteCore migration.
Resources	MRT	MRTCore	For more info, see MRT to MRTCore migration.
.NET Runtime	.NET Native / C# 7	.NET 6+/C# 9	The Windows App SDK provides access to the modern .NET runtime, and access to new language features. However, .NET ReadyToRun compilation is not the same as .NET Native, so you should evaluate performance tradeoffs.
2D Graphics	Win2D	Win2D for WinUI 3	We're currently working on a version of Win2D that works with the Windows App SDK, in progress. See the documentation for more information.
Windows Runtime components	Windows Runtime component project templates for UWP	- C++: Use the Windows Runtime Component (WinUI 3) project template. - C#: Use C#/WinRT to author Windows Runtime Components in a .NET Class Library.	We're currently working on support to Author Windows Runtime Components using C#/WinRT for use in the Windows App SDK and WinUI 3.