Windows App Development Frequently Asked Questions

For a great review of today's options for Windows developers, watch the most recent Windows Dev Chat episode, Choosing your ideal dev platform, where they discuss WinUI, .NET MAUI, React Native, Blazor, and Progressive Web Apps (PWAs).

You can also refer to the overview of app development options for Windows developers.

In the age of cloud services, client app development remains a critical component of modern digital transformation. For developers, building client applications is essential not just for reach but for delivering responsive, meaningful interactions on user devices.

Here's why client apps matter:

• Device Reach: With over 1.5 billion Windows devices and more than 5 billion Android and iOS devices globally, client apps let you bring your applications directly to users on their devices of choice.
• Gateway to Intelligent Services: Client apps are often the first interaction users have with your services. They offer a rich, interactive interface that allows you to showcase intelligent features and differentiate your product from others.
• Scalability with Cloud Integration: A well-integrated client app can sync effortlessly with backend cloud services, enabling real-time data access and seamless scalability as your user base grows.
• Enhanced Productivity and User Loyalty: A thoughtfully designed app can enhance productivity and keep users engaged with your product or service over time.

The Windows App SDK is a Windows application development platform that allows you to create beautiful, modern, backwards-compatible (down to Windows 10 1809) desktop apps. WinUI is the UI framework that ships with Windows App SDK.

Both are software development kits (SDKs) that let you build Windows apps.

The Windows App SDK is a new development platform that lets you build modern desktop apps that can be installed across Windows versions (down to Windows 10 1809). When building with Windows App SDK, the latest Windows development platform features are available. The Windows App SDK includes WinUI.

The Windows SDK is a development platform that lets you build UWP apps and Win32/desktop apps. It's designed around Windows APIs that are coupled to particular versions of the OS.

The Windows App SDK doesn't replace the Windows SDK. Instead, the Windows App SDK complements the Windows SDK. It provides a convenient, OS-decoupled abstraction around the rich catalogue of Windows OS APIs that are already accessible using the Windows SDK. Apps built with Windows App SDK may still use Windows SDK APIs depending on functionality needs. Over time, more Windows SDK functionality will move into the Windows App SDK.

Here are some reasons to choose a native Windows framework for your Windows-only app:

• Performance: Native Windows frameworks are optimized to leverage modern Windows hardware, providing fast and responsive user experiences.
• Integration: Windows ships with a wide variety of APIs that enable sophisticated experiences only available on Windows. Native frameworks provide deep integration with these features and APIs.
• Native user experience: Native frameworks provide a consistent experience across Windows devices, ensuring that your app looks and works great everywhere.
• Offline support: Native frameworks support offline scenarios, allowing apps to function even without internet connectivity.
• Monetization: Native frameworks are actively maintained and supported by Microsoft, ensuring access to the latest updates and features.

If you're building a new Windows-only app, we recommend using WinUI. WinUI is the latest native UI framework for Windows app development and is designed to work across a wide range of Windows devices. It provides a modern and flexible UI framework for creating visually appealing and interactive Windows apps. WinUI is part of the Windows App SDK and works best with the latest versions of Windows.

Note that WinUI (a UI framework) ships with the Windows App SDK (a Windows platform development framework).

Generally, WinUI can't be used unless the app is ready to migrate its UI framework entirely. A feature called XAML islands is in development to host WinUI content in other UI frameworks (WPF, Win32).

Elements of the Windows App SDK can often be used in desktop apps, depending on how the existing app was built. UWP apps are not supported by Windows App SDK.

This means WPF/MFC/WinForms apps can use Windows App SDK APIs that are unrelated to WinUI. Examples include App Lifecycle, Windowing, and Toast Notifications.

See Use the Windows App SDK in an existing project for more info.

Using Visual Studio 2022 version 17.10 or above is strongly recommended for WinUI development. The latest Visual Studio versions offer rich development features like Hot Reload and include a WinUI application development workload that simplifies setup.

Other IDEs and workflows may work, but Visual Studio is currently the only officially supported IDE for WinUI. Note that MSBuild is required to compile XAML or WinUI projects.

WinUI is the latest native UI framework for Windows app development. It provides a modern and flexible UI framework for creating visually appealing and interactive Windows apps. WinUI is part of the Windows App SDK and works best with the latest versions of Windows.

WinUI 2 is a set of UI controls and styles built on top of UWP. It provides a modern look and feel for UWP apps and is designed for Windows 10.

WinUI 3 was the earlier name for WinUI when it first shipped as part of the Windows App SDK.

In summary, WinUI is the latest and most advanced version of the WinUI framework, WinUI 2 is a control library for UWP, and WinUI 3 was an earlier label for WinUI. Use “WinUI” going forward unless specifically referring to WinUI 2.

Yes — “WinUI app” is the recommended term. WinUI apps are referred to as “WinUI apps” because WinUI 2 is not a type of app but a set of components used in UWP apps.

No. Windows App SDK can't be used in UWP apps, and WinUI 2 can't be mixed with WinUI. See Migrate from UWP to the Windows App SDK.

Migrating UI components is generally straightforward (for C# and C++/WinRT). Otherwise, migration cost depends primarily on:

1. Project file and MSBuild customization: Migration effort varies depending on advanced MSBuild usage.
2. .NET API migration: UWP apps using .NET must move to .NET 6 or later. In many cases, adopting .NET 6 is straightforward.
3. UI component libraries: Libraries must have versions targeting WinUI.
4. If the UWP app is written in the now-superseded C++/CX, some source code porting is required. See Move to C++/WinRT from C++/CX.

For more info, see Migrate from UWP to the Windows App SDK.

Yes, upgraded apps can be published without updating the application identity. Users of the old version will be updated to the new version. This applies to desktop apps only. Xbox, HoloLens, and Surface Hub apps cannot migrate to WinUI.

See Deployment overview.

See Migrate from UWP to the Windows App SDK.

No. UI controls can be created in code. However, representing the UI in declarative XAML markup provides many benefits, including an improved developer experience.

• Migrating from UWP to WinUI: Many XAML and UI components can be reused, though some syntax adjustments are required.
• Migrating from WPF to WinUI: Many concepts carry over, but the control set and APIs differ.

Not yet. This is a known gap in the WinUI developer experience. Tools like XAML Hot Reload can help in many scenarios. Work has started on a Visual Studio UI designer for WinUI in Windows App SDK 1.7, but there is no timeline yet for its release.

Yes. WinUI ships as part of the Windows App SDK.

No. WinUI 2 is part of the UWP platform.

Not quite. Although WinUI originally started from the WinUI 2 codebase, they are distinct technologies. Both are XAML-based UI frameworks that work across .NET and C++, but WinUI 2 and WinUI are not compatible with each other.

No. WinUI ships as part of the Windows App SDK.

Yes. All technologies in the Windows App SDK, including WinUI, work in unpackaged apps.

XAML Islands let you host modern XAML-based controls alongside existing Win32 UI from other frameworks such as WinForms and WPF.

Today, XAML Islands support most system XAML and WinUI 2 controls. See Host WinRT XAML controls in desktop apps (XAML Islands) for more details. Support for hosting WinUI controls is available starting in Windows App SDK 1.4.

Yes. Your app’s UI will inherit the latest Fluent UI design principles on all supported versions of Windows 11 and Windows 10, down to version 1809, in both packaged and unpackaged scenarios.

Yes. See Apply Mica or Acrylic materials in desktop apps for Windows 11.

See Sample and resources. Some notable repositories:

• WindowsAppSDK-Samples: Demonstrates how to use specific Windows App SDK API sets.
• Windows topic-specific samples: Contains a WinUI notes sample used in the Create a WinUI app tutorial.
• WinUI Gallery: Showcases WinUI and Windows App SDK. Also available in the Microsoft Store.

If you've already invested heavily in WPF, you can continue using it for existing apps. WPF is a mature, stable framework widely used to build Windows desktop apps.

Consider using the .NET Upgrade Assistant to migrate .NET Framework WPF apps to the latest .NET platform. It analyzes your codebase and provides guidance on updating it.

When developing a WPF application with .NET 9 or later, you can ensure your app matches the sleek, modern look of Windows 11. The new Fluent theme for WPF introduces a contemporary Windows 11 aesthetic, with integrated Light/Dark mode and system accent color support. This modernizes your app’s appearance and delivers a polished, cohesive user experience.

If WinForms meets your needs and your team is comfortable with it, you can continue using WinForms for existing apps. WinForms is a mature and stable framework widely used for Windows desktop development.

The WinForms team continues to invest in the platform. Some current areas of investment include:

• Async support for common controls
• Dark mode
• Layout flexibility
• Desktop security features such as clipboard access

If you're targeting users across multiple OS platforms, building cross-platform apps with .NET MAUI or React Native can offer several benefits:

• Reach: Cross-platform apps reach a larger audience across different devices and operating systems.
• Code reuse: Reusing code across platforms reduces development time and cost. Building separate apps for Windows, Android, iOS, and macOS can be prohibitively expensive.
• Consistent user experience: Cross-platform frameworks help provide a consistent look and feel across platforms.
• Integration: Cross-platform apps can still integrate with platform-specific services to deliver a comprehensive experience.

When you build a .NET MAUI app for Windows, the output is a WinUI app. During development, .NET MAUI offers a single .NET experience across platforms, but it generates platform-specific code under the hood. This ensures that .NET MAUI apps perform well on each platform and deliver a native user experience.

.NET MAUI provides a unified .NET experience across Windows, iOS, Android, and macOS. It abstracts over 60 platform-specific APIs into a single cross-platform API set, covering areas like storage, networking, and device sensors. Additional platform-specific APIs can also be accessed using dependency injection to provide specialized implementations per platform.

Not at this time. Although .NET MAUI uses WinUI when running on Windows, teams expecting to target multiple platforms should start with .NET MAUI or React Native for Desktop.

Teams with strong web development experience may want to consider React Native for Desktop. It includes React Native for Windows and macOS. With the “Learn once, write anywhere” approach, existing JavaScript, TypeScript, and React skills can be used to build native Windows and macOS apps.

React Native for Desktop renders UI directly to native primitives, delivering native performance and platform capabilities.

See the React Native for Desktop documentation to get started.

React Native apps can be deployed to all devices supported by Windows 10 and later, including PCs, tablets, 2-in-1s, Xbox, and mixed reality devices.

If your app needs to support Xbox, HoloLens, or IoT, UWP is recommended. Windows App SDK does not support these platforms. For game development, use the Microsoft Game Development Kit.

If you're targeting both Windows and Surface Hub, UWP is recommended.

Hybrid apps blend the best of web and native app development. Their core is built using web technologies like HTML, CSS, and JavaScript, and wrapped in a native container that gives access to certain native platform features and hardware. They can also be distributed through app stores.

The main advantage is that hybrid apps allow you to build a single app that can run on multiple native platforms and on the web, reducing development time and cost. Examples of hybrid app development platforms include:

• Electron for desktop apps
• Ionic for mobile apps
• .NET MAUI Blazor Hybrid for cross-platform apps

See Web development on Windows and Overview of Progressive Web Apps.

With .NET MAUI, Blazor apps can run natively on Windows, iOS, Android, and macOS. This allows you to create hybrid client apps that combine Blazor and .NET MAUI components in a single native client app, with full access to native platform capabilities.

Learn more at ASP.NET Core Blazor Hybrid.

No. Starting with .NET 9, .NET MAUI includes a HybridWebView control that allows hosting other JavaScript-based UIs inside a native app.

This allows you to host Angular, React, Vue, or other HTML/JavaScript apps inside a .NET MAUI app. The hybrid control provides interop between C# and JavaScript, so C# code can call JavaScript functions and vice versa.

Yes. WPF and WinForms apps can also host Blazor hybrid components, enabling the addition of modern web UI to existing apps. This is not supported for WPF or WinForms apps built on .NET Framework.

Native and hybrid components can be mixed within an app. For example, the core of an app may be built with .NET MAUI components while hybrid components provide additional functionality. This allows combining the performance and capabilities of native components with the flexibility and cost efficiency of hybrid components.

Web apps offer the broadest reach of any client app platform. Options for creating beautiful .NET web apps include:

• ASP.NET Core apps with Razor Pages
• ASP.NET Core MVC apps
• ASP.NET Core Blazor apps, with hosting model options:
  • Blazor WebAssembly
  • Blazor Server

Blazor hosting models can now be configured at the component level, enabling scenarios like hosting a Blazor WebAssembly component within a Blazor Server app.

See the ASP.NET Core documentation for more details.

Windows is an open platform that supports many technologies. Here are some criteria that can help you choose a platform:

• Are you building Windows-first or cross-platform?
• What languages or skills do you already have — .NET, JavaScript, something else?
• Do you need access to Windows-specific APIs?
• Which framework’s capabilities best match your app’s requirements?
• See this table for additional comparison factors.

For many business apps, teams often choose based on existing skills and what the team is most comfortable using.

Consider the following when choosing a development approach for your web app:

• Blazor is recommended for building front-end web apps with .NET. It lets you build both the front-end and back-end using .NET, saving time and cost, and it’s especially good for enterprise apps.
• JavaScript web apps still make sense if you want to leverage existing JavaScript skills or need to integrate with established JS libraries or frameworks.
• Existing apps using older frameworks like Web Forms, MVC, or Razor Pages remain supported and can continue to be developed and maintained.

Many customers are building with WinUI today, including Adobe and Apple:

• Adobe Fresco, a free drawing and painting app.
• Apple’s Apple Music, Apple TV, and Apple Devices apps were built with WinUI and the Windows App SDK.

Microsoft has also built many WinUI apps, such as Windows 11 File Explorer and the Photos app.

Many customers, including Microsoft, are building cross-platform apps with .NET MAUI. For example, the Microsoft Azure mobile app is built using .NET MAUI.

See more on the .NET customer showcase.

Most of the Microsoft Visual Studio UI is built with WPF. The Visual Studio IDE itself is a major example of a complex, high-performance WPF app.

GE Digital’s FlightPulse airline system uses Blazor for the backend configuration of everything pilots see, bringing sensor data and analytics directly to pilots to improve safety and efficiency.

See more Blazor customer stories on the .NET site.

Yes. If your MSIX package is signed, the signing certificate must be valid and trusted on the target device.

Yes — XAML Islands enables this. See Learn more about XAML Islands.

For definitions of packaged, unpackaged, and packaged with external location apps, see Deployment overview. That topic also explains the advantages and disadvantages of each option.

A WinUI app can be delivered through the Store, an .appinstaller file, or through an existing MSI or setup.exe package. The Store and AppInstaller support automatic updates for end-users who have automatic updates enabled, but MSI/setup.exe apps must provide their own update mechanism.

Generally, no. WinUI and the Windows App SDK require MSBuild, which is why Visual Studio is a prerequisite for developing with them. While it is technically possible to build Windows App SDK apps that don't use WinUI with other toolchains, this isn't supported.

See Make apps great for Windows.

Users with Windows 10, version 1809 or later can install WinUI apps without updating their OS.

Yes.

No. UWP and WinUI 2 are still supported and continue to receive bug, reliability, and security fixes. However, most new features and capabilities are added to WinUI.

UWP support for .NET 9 is available. This option provides a modernization path for UWP apps using the latest .NET version.

The goals of .NET 9 UWP support are:

1. Provide a better migration path for developers who want to move to WinUI.
2. Remove dependencies on .NET Native so developers can benefit from the latest .NET and C# features.

For more information, see the blog post: Modernize your UWP app with preview UWP support for .NET 9 and Native AOT.

UWP developers should not feel pressured to migrate if they are satisfied with UWP and its feature set — for many apps, the right choice may be to stay on UWP.

Apps that want to benefit from the latest Windows platform and .NET investments should consider moving to the Windows App SDK. See Migrate from UWP to the Windows App SDK.

Continue using UWP if you're building for Xbox, Surface Hub, or HoloLens.

No. WPF is supported, recommended, and continues to receive feature updates. See the WPF roadmap on GitHub.

No. WinForms is supported and continues to receive feature updates. See the Windows Forms Roadmap on GitHub.

No. WinRT is an application binary interface (ABI) that enables interop across multiple languages. WinRT is the evolution of COM, and the Windows App SDK provides most of its functionality through WinRT APIs.

See Stable channel release notes and Preview channel release notes.