Microsoft Officially Deprecates UWP

Posted on October 19, 2021 by Paul Thurrott in Dev, Windows 10, Windows 11 with 32 Comments

Microsoft continues to baby-step around the obvious, but it has officially deprecated the Universal Windows Platform (UWP) as it pushes the desktop-focused Windows App SDK (formerly called Project Reunion) and WinUI 3 as the future of Windows application development.

“The Windows App SDK is focused on empowering developers to build the most productive apps on Windows,” Microsoft’s Thomas Fennel explains. “To achieve this, we are using the existing desktop project types [and not UWP] as the foundation of the Windows App SDK, due to the vast amount of existing desktop APIs and compatibility that desktop project types provide.”

(Thanks to Rafael Rivera for pointing out this documentation on Twitter.)

For those unclear on the matter, the Windows App SDK basically takes key UWP technologies and new technologies like WinUI 3 that will not be backported to UWP and makes them available to developers in a way that is not tied to specific Windows releases (as was the case with individual UWP features). In this way, Microsoft can “deliver on the agility and backward compatibility developers need to reach across the entire Windows ecosystem” while not leaving developers behind.

Going forward, UWP will only receive “bug, reliability, and security fixes,” and not new features, Microsoft says, indicating that it is now deprecated. Developers with UWP apps in the market who “are happy with [the] current functionality in UWP” can of course continue to keep using UWP. But those who want “the latest runtime, language, and platform features,” including WinUI 3, WebView 2, .NET 5, full compatibility with Windows 10 version 1809 or newer, and any upcoming new features will have to migrate their apps to the Windows App SDK.

I know this is a controversial topic for some. But to reiterate the obvious, Microsoft told the press years ago, literally, that it was killing UWP. And despite its mealymouthed public non-explanations about this topic, this new information represents an official and public confirmation that it has taken the first official step towards the future of Windows app development. Which is desktop apps built with Windows App SDK, and not UWP.

The good news, of course, is that developers who invested time in learning UWP and creating UWP apps can apply their knowledge and experience to creating new Windows App SDK apps or migrating existing apps to this improved and fully supported platform. This is one of Microsoft’s greatest strengths as a platform maker, I think: its ongoing dedication to not leaving developers behind. So while UWP may be transitioning to the maintenance phase of its lifecycle, those who support it can keep moving forward. Folks, that’s good news.

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Comments (32)

32 responses to “Microsoft Officially Deprecates UWP”

  1. fsdfdsfsdf

    Those 15 developers will be happy to learn they don't have to rewrite their programs once again to another framework

  2. matsan

    wow! Deprecating a framework but not introducing a new!!??! That’s a first. They have run out of them?

    • usman

      You can migrate UWP apps to Windows App SDK. It'll be a multi-step process but anyone maintaining an application should have done the following already:

      • Move libraries to .Net Standard 2.0
      • Move UI to WinUI 2

      Once those things are done then moving to the Windows App SDK / Win32 execution model will become easier to do.

  3. madthinus

    What is Hololens developers going to use. I assume Hololens V4 would then have a new software stack? Or are they just not going to innovate further in that space?

    Xbox cross gen probably already have made a switch to something that runs native on both platforms.

    • usman

      I've got similar questions as well.

      With Hololens most of the underlying platform stuff is abstracted away by Unity and Unreal engine. The development story for Hololens is to use MRTK on Unity or Unreal, currently, they're built as UWP apps, so I wonder if they will compile to the regular Win32 runtime.

      Xbox is also an interesting one, what happens to sideloading, and if they do kill that feature. I wonder if there is a future for homebrew on Xbox outside of UWP runtime apps.

  4. winner

    I thought only Google discontinued things?

    • Greg Green

      You are new to the pc world, aren’t you?

      • winner

        Actually not at all, I probably had a PC before you were born unless you are of my vintage.

        I was joking about how everybody dumps on Google for discontinuing things.

  5. shameer_mulji

    Just curiuos. If a new developer is coming want to develop apps for the MS ecosystem, why would they create an app using Windows App SDK, which will only run on Windows, when they can create an app using MAUI which can run on Windows, Mac, iOS, iPadOS, Android, and web?

    • usman

      That argument also applies to any new app project that is cross-platform. You wouldn't use Swift and Java/Kotlin.

      You would use a cross-platform SDK like React Native, Flutter, and Xamarin/Maui. Those then target the respetctive platforms, including App SDK on Windows.

  6. rob_segal

    UWP has been zombified for years now. We were just waiting for it to be made official.

  7. Jogy

    Not surprised. UWP lost it's reason for existence with the killing of the Windows Mobile/Phone platform.

    After that, it's name became a lie - how can a platform be "Universal" when it was the most restricted of all the UI platforms there:

    WinForms/WPF can run on all versions of Windows (7, 8, 10)

    Xamarin (and now MAUI) can run on the main mobile platforms (Android/iOS) plus Windows desktop

    UWP can run ONLY on Windows 10 (and XBox, but - who cared?)

    • shameer_mulji

      But HoloLens and Xbox still rely on UWP

      • Jogy

        Does it make sense to have a single binary that would run on Windows desktop, Xbox and Hololens? That was the promise of UWP.

      • hrlngrv

        Xbox relies on UWP? Xbox games are all UWP? Alternatively, lots of people using UWP weather apps on their Xboxes?

  8. hrlngrv

    What a disappointment for the hundreds of UWP app users!

    Was this not inevitable once MSFT killed off Windows phones? Shouldn't the greater mystery be why it took so long?

    As for the experience developers amassed learning UWP, they can add that to the experience they or other developers amassed learing SilverLight and lots of other development models MSFT has deprecated over the years and reach the obvious conclusion: never trust MSFT. Or perhaps that should be, developers who trust MSFT can expect all the success of Lotus Development Corp and Ashton-Tate.

    Aside from MS Office, I spend the most time using Firefox and RStudio. Dunno what Firefox uses, but since its desktop version runs under Windows, macOS and Linux, it should be safe to surmise that it uses no Windows-only APIs. Same likely true for other browsers, excepting Edge. OTOH, I know RStudio uses Qt, as do a few other programs I use less frequently, also with Linux versions.

    I suspect a sizable minority if not an actual majority of developers avoid Windows-only APIs whenever possible, leaving their use primarily in the hands of in-house developers who formed the cadre of professional Visual BASIC developers.

    May WinUI 3 receive all the usage UWP has. Anyone up for a pool for when MSFT deprecates it?

  9. saint4eva

    Executive Summary:

    Windows App SDK (WinAppSDK) is the superset of Universal Windows Platform (UWP).

    • Paul Thurrott

      We're not rearguing this. Windows App SDK is desktop-based and it's decoupled from specific Windows releases. It's a lot more than a UWP superset. It's what UWP should have been in the first place.

      • spiderman2

        For the moment is just a slower, heavier and hungrier UWP superset... I don't know what you mean by "desktop-based" but can I reach better results with UWP. One thing I agree, decoupling it from windows release is good

      • sledge

        Win devs are always the last to accept the inevitable. UWP is gone, just servicing now. It really is time to move on after multiple failed, weird, half arsed attempts at one codebase to rule them all.

        Look at how Maui has slipped. Look how poor xamarin has been (Nightmare land of weird untraceable issues with every release).

        Source: Xaml dev from WPF\Silverlight days (Who now just does backend)

  10. Informed

    rmac, opening this page in Windows 10 Edge (V. 94) I don't see "big white space gaps." Are you running the legacy Edge, or the newer Chromium-based one?

  11. rmac

    Paul, can you please fix those big white space gaps between paras so we can sensibly comment (Edge W10)? Many thanks.

  12. DavidSlade

    Reminds me of Silverlight: For a while Microsoft said it was the greatest thing ever. Then suddenly they fell silent about it. Never said it was dead, but we all got the message.

  13. jupast

    Maybe Ego Rubino and his buddy over at Windows Central can get over themselves now and stop insisting it's 'not dead!' and 'We're right and you're all wrong!' because there's one line of UWP code drifting around in a subset that Microsoft uses somewhere.

    But they probably won't.

  14. winner

    "mealymouthed public non-explanations"

    Now THAT'S a perfect term for Microsoft's Marketing.

    • hrlngrv

      Mealymouthed is when MSFT is feeling too lazy for obfuscation or deliberate deviousness.

  15. Bart

    As someone who is not familiar with dev platforms; how does security factor into all this? I thought one of the greatest benefits of UWP was security. Is this the same for the Windows App SDK?

    • jimchamplin

      It encompasses everything that was in UWP, and adds to it. As some have said, a superset, but also with a new focus on desktop development.

      • SvenJ

        Which makes sense since they have mobile windows platforms. Even their 'tablets' are becoming TINO (Tablet in name only).

  16. ronmcmahon

    Paul, I have to disagree with your assertion

    This is one of Microsoft’s greatest strengths as a platform maker, I think: its ongoing dedication to not leaving developers behind.

    Microsoft utterly betrayed and abandoned classic VB developers with its wholesale .NET initiative. Since then the domain of software development has become one of bloatware and feature failure, where apps barely perform as promised and are subject to unannounced and forced wholesale functionality and UI changes (Teams anyone?).

    Yes, I'm a grumpy old developer, but I can say that the current state of software development is not an improvement over the past. It's like we've taken our cars and have removed every part that made them safe and effective transportation and have replaced only some of these parts with items of dubious quality, unknowable functionality and mysterious origin.

    It isn't difficult to imagine how our current computing ecosystem is ripe for attack and widespread failure through the activation of deeply embedded malicious code.