Microsoft adding support for running multiple instances of UWP Windows 10 apps

Microsoft will soon allow developers to support opening multiple instances of their Universal Windows Platform (UWP) apps on Windows 10. The feature will be available to all starting with the upcoming Redstone 4 update (version 1803), and it is currently supported in the latest Windows 10 Insider build and SDK (via Neowin).

In a new post on the Windows Dev Center (opens in new tab), Microsoft offers examples of how developers can implement multi-instancing and how it will work. From Microsoft:

Prior to Windows 10, version 1803, only one instance of a UWP app could be running at a time. Now, a UWP app can opt-in to support multiple instances. If an instance of a multi-instance UWP app is running, and a subsequent activation request comes through, the platform will not activate the existing instance. Instead, it will create a new instance, running in a separate process.

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Besides allowing multiple instances of the same app to be opened, developers will also be able to customize the experience a bit. For example, in a case where two instances of an app are open, developers can specify whether they want to prevent each instance from working on the same file. Or, if an app is launched for a file that is already open, developers can force a redirect to the instance that already has the file open.

Multi-instance support has already been supported for some time in specific Microsoft UWP apps, including Calculator and OneNote. However, expanding the option to all developers will tackle one of the more frustrating issues with using UWP apps over their desktop counterparts.

For more, check out Microsoft's full developer documentation (opens in new tab) as well as the most recent Windows Community Standup.

Dan Thorp-Lancaster is the former Editor-in-Chief of Windows Central. He began working with Windows Central, Android Central, and iMore as a news writer in 2014 and is obsessed with tech of all sorts. You can follow Dan on Twitter @DthorpL and Instagram @heyitsdtl

49 Comments
  • Yes! Finally!
  • It is amazing to me how much more nerfed UWP is in basic ways compared to classic Windows apps. They are not as snappy are a bit sluggish, have odd usability issues and bugs (sometimes the clipboard doesn't seem to work as expected). I don't know where Microsoft's dev team has been, but it seems like it is second rate these days. Maybe all the good devs are working on Azure.
  • You just don't get it. Running 2 caclulators at once is a great achievement.
  • Question: Hit Windows key nd type calc... is that Calculator an UWP app?
  • Classic windows has years of foundation and development. UWP is a complete rebuild, people always expect Rome to be built in a day. That being said, I'm glad this is coming!
  • That can be but you can't expect shops (developers) and tourists (users) to arrive en masse when your city is still in full development stage.
  • They stayed this Modern App thing 6 years ago. Don't you think that's enough?
  • UWP is 2.5 years old only, it's not the same thing as Metro/Modern apps as evidenced by the fact that the former doesn't feature the compatibility charms button on the left of their title bars.
  • It's not the same thing exactly, but UWP builds on WinRT. It's like a 2.0 (or 3.0 at this point, I guess).
  • Today you could easily build 90% of most common used apps in a proper way in UWP ... if you really want
  • H1B. Notice how development quality took an absolute nosedive after Satay took over... yeah well that's why.
  • Oh thank god. It's about time.
  • Wouldn't it be awesome if they even supported tabbed shell feature?
  • They Should add Drag 'n drop already !!!
  • It is supported, has been for over a year based upon the time stamp on article: https://docs.microsoft.com/en-us/windows/uwp/app-to-app/drag-and-drop
  • Why none of Microsoft own apps use it then? Sad really.
  • This is not true, at the very least Edge, Mail and Calendar and OneNote use it.
  • Office also has an UWP version right?
  • lol, interesting, because it still doesnt work in most of apps :-/
  • Developers still need to implement it in their apps, UWP can't decide what the intent of drag and drop of any element to another place. But just because they can doesn't mean they should. For example, I can drag and drop a link from Edge to the desktop and other places. Drag and drop a button from one app to another doesn't make sense, and shouldn't be forced just to say they support drag and drop.
  • Right, that makes sense, thanks.
  • Whats taking them so long to add these basic features? Does this mean we can drag and drop files into these windows now?
  • Drag and drop has nothing to do with that and anyway, it has been available since 1511, if I recall right.
  • Its not available on any of my devices, not even the insider build. Try dragging any PDF file into Edge, audio file into Groove, image into Photos, bookmark bar page or link out of Edge on to your desktop.
  • Yes! I can finally play Minecraft with myself! :)
  • This guy knows what's up. Now we can open 2 calculators and do 2 problems at once too. Windows 10 is so much more advanced than older versions like Windows 98. I bet you couldn't even open 2 programs at the same time back then.
  • can't we already open 2 calculators? (ctrl+r -> calc -> enter) * 2, you get 2 clac.
  • I'd like to see an article about the long term plans for UWP. Havent heard much lately aside from this. UWP can be done well... Groove app was great.
  • UWP will basically be replaced by PWA. Lots of tech sites already did articles about this the past month
  • No, it won't, any task that requires performance, like games, will still require native code.
  • Yep. Actually, I would want all my apps to run native code. No wonder the iPhone feels so snappy. JIT, CLR, IL VM whatever they use in Windows and Android just eats away precious processor cycles!
  • The iPhone is fast. But what Edge even on a lumia 550 can do (as faster as Chrome on a Galaxy S7) is impressive. In my opionion: An optimized website is the better choise over 3 badly made apps and a website.
  • UWP are compiled natively a long time now. The appropriate executable (arm, x86, x64) is downloaded from the store when you download the app.
  • Plus, a game takes several GBs to DL, you don't want to store that in your memory either. You want to keep the logic in the mem but store all your resources in the disk for later use.
  • Hasn't that been supported for a very very long time already since you can open multiple instances of Calculator for example? And since Microsoft has stated that they'll always be using the very same SDKs that they give out to the public, this should be do-able already. Maybe it was just a hidden feature of some sorts, unless Microsoft has been lying to us :)
  • This is explained well in Microsoft's blog post, not as much here. For many Updates now we've been able to open many Calculator windows, but all of them amounted to just one process; RS4 changes that, giving UWP apps the ability to open as many processes as needed.
  • > Multi-instance support has already been supported for some time in specific Microsoft UWP apps, including Calculator and OneNote. Are you sure that wasn't just multi-window support and what is being added now is actual multi-instance support?
  • They go about it the wrong way. It should default to multiple instances and have the dev code if they want to prevent it.
  • I sure hope Microsoft's own Settings app will support it from the start, if there is an app I want to have multiple instances that's the one.
  • Multi-instance support has already been supported for some time in specific Microsoft UWP apps, including Calculator and OneNote.
    Bull ****, they are not.
  • Will this allow me to have multiple accounts signed in on a social media app? Like I can open FB (or a FB client) twice to sign into two different accounts?
  • If FB wants you to. Otherwise, no.
  • Yes. Yippi. I'm so excited. Now the developers not developing UWP applications for users not using UWP applications can continue to not make apps that don't implement multiple instances. UWP is dead and not the future of Windows applications. PWAs take  the pressure off developers to support UWP. Why would you devote resources to developing for UWP and target only Windows users when you could make a PWA for the same effort and expense that is platform agnostic?
  • Dedicated apps, while they may lessen, won't be totally going away even when PWA is first released. If you need advanced features then a dedicated app may be more appropriate including UWP.
  • "Why would you devote resources to developing for UWP and target only Windows users when you could make a PWA for the same effort and expense that is platform agnostic?" Because there are many use cases, like gaming and video editing, where performance is key and PWAs simply aren't performatic enough for the task.
  • Setting app should be really useful
  • At first, UWP was designed for mobile apps. It lacks many functions necessary for desktop apps. This is one of them.
  • Finally! This is great news for alot of people and those of who actually make use of the virtual desktops for their work flow along with UWP apps and Win32 apps.
  • Wow, I thought they already could do that, shows how much I used a UWP then. So if a mate of mine went over to Windows 10 and used Edge he would be stuffed, he can not stand tabs and prefer to have different Windows open. I did try and get him to use Tabs, but i had no luck.