Blazor 0.9.0 experimental release now available

Daniel Roth

Blazor 0.9.0 is now available! This release updates Blazor with the Razor Components improvements in .NET Core 3.0 Preview 3.

New Razor Component improvements now available to Blazor apps:

  • Improved event handling
  • Forms & validation

Checkout the ASP.NET Core 3.0 Preview 3 announcement for details on these improvements. See also the Blazor 0.9.0 release notes for additional details.

Note: The Blazor templates have not been updated to use the new .razor file extension for Razor Components in this release. This update will be done in a future release.

Get Blazor 0.9.0

To get started with Blazor 0.9.0 install the following:

  1. .NET Core 3.0 Preview 3 SDK (3.0.100-preview3-010431)
  2. Visual Studio 2019 (Preview 4 or later) with the ASP.NET and web development workload selected.
  3. The latest Blazor extension from the Visual Studio Marketplace.
  4. The Blazor templates on the command-line:

    dotnet new -i Microsoft.AspNetCore.Blazor.Templates::0.9.0-preview3-19154-02

You can find getting started instructions, docs, and tutorials for Blazor at

Upgrade to Blazor 0.9.0

To upgrade your existing Blazor apps to Blazor 0.9.0 first make sure you’ve installed the prerequisites listed above.

To upgrade a Blazor 0.8.0 project to 0.9.0:

  • Update the Blazor packages and .NET CLI tool references to 0.9.0-preview3-19154-02.
  • Update the remaining Microsoft.AspNetCore.* packages to 3.0.0-preview3-19153-02.
  • Remove any usage of JSRuntime.Current and instead use dependency injection to get the current IJSRuntime instance and pass it through to where it is needed.

Give feedback

We hope you enjoy this latest preview release of Blazor. As with previous releases, your feedback is important to us. If you run into issues or have questions while trying out Blazor, file issues on GitHub. You can also chat with us and the Blazor community on Gitter if you get stuck or to share how Blazor is working for you. After you’ve tried out Blazor for a while please let us know what you think by taking our in-product survey. Click the survey link shown on the app home page when running one of the Blazor project templates:

Blazor survey

Thanks for trying out Blazor!


Discussion is closed. Login to edit/delete existing comments.

  • Sven Glöckner 0

    Thanks for this great announcement. I guess it’s not long to have v1.0 😉 

  • Przemysław Kamiński 0

    Better minimise assembly size and increase performance. You will do that before v1.0 or 2/3/4? 😂😂

  • Baran Ozdemir 0

    Thanks Dan, I updated my experiental projects to the latest version, it is great to see we are getting forms and validation.

  • Chipo Hamayobe 0

    Thanks Daniel for the update.
    Any timetable yet on when we will see a non-experimental release? 

  • Baran Ozdemir 0

    Hi Dan, 
    I am getting this error when i restore nuget packages when I build the solution on Azure DevOps pipeline. 

    The nuget command failed with exit code(1) and error(NU1202: Package Microsoft.AspNetCore.Blazor.Cli 0.9.0-preview3-19154-02 is not compatible with netcoreapp2.2 (.NETCoreApp,Version=v2.2). Package Microsoft.AspNetCore.Blazor.Cli 0.9.0-preview3-19154-02 supports: netcoreapp3.0 (.NETCoreApp,Version=v3.0)
    Errors in D:\a\1\s\Web.Customer.csproj
    NU1202: Package Microsoft.AspNetCore.Blazor.Cli 0.9.0-preview3-19154-02 is not compatible with netcoreapp2.2 (.NETCoreApp,Version=v2.2). Package Microsoft.AspNetCore.Blazor.Cli 0.9.0-preview3-19154-02 supports: netcoreapp3.0 (.NETCoreApp,Version=v3.0))



    Packages failed to restore

    • Rob de Voer 0

      Hello Baran,
      You need to install .NET Core 3.0 Preview 3 SDK (3.0.100-preview3-010431) for blazor 0.9.0 to work.
      The installation and upgrade steps are described in the two paragraphs above.

      • MIchael Bowles 0

        I have the same error with the creating the first Blazor project type (project template for standalone Blazor on WebAssembly) and on the other type Blazor(APS.NET Core hosted) I get an error that it needs core 3.0 Preview 3 SDK (3.0.100-preview3-010431), which is installed.   Neither will compile or run.
        Update: Was able to get things running by followling this post on the developer network.
        Will Vasquez · Jan 09 at 12:33 AM 0 



        Not very obvious but if you go to Tools -> Options and search for .NET Core you’ll see a checkbox that says “Use previews of the .NET Core SDK”. After checking this I was able to load the projects just fine.

        • Chris DePalma 0

          Thanks, that fixed it.  Still has 66 errors but runs anyway. Strange.

      • Baran Ozdemir 0

        Rob thanks for your response. I believe Azure DevOps does not support 3.0 preview yet so I am publishing it from VS directly to Azure App Service, works perfectly. We have finished our first pilot project, which has almost everything you would need for a typical web application (file upload, file download, local storage, treeview, modal pop-ups, confirmation dialogs, etc). It looks very promising. We are looking forward to using production version very soon. 

  • Daniel Smith 0

    Are there plans to eventually have a nice experience when right clicking the project in Visual Studio and choosing Add?  At the moment, the two top level options are Razor Page and Controller, both of which produce an error (“There are no scaffolders supported for this item”).
    It would also be great if the Add > New Item dialog defaulted to an appropriate file type, and for the template file to at least have an empty @functions section.  Or when code behind files are implemented, if the New Item dialog could create the markup and nested code behind that would be even better 🙂

  • Eric Blankenburg 0

    I downloaded 0.9 the day it was release. It’s so easy to develop a single page app compared to Angular 7 and React. Compiling and running the code is also much faster than Angular. When are you going to remove the “experimental” designation and decidate to releasing it as a product?

  • Martin Kremer 0

    Does ist work with the VS 2019 RC or just with the VS 2019 Preview (4 or later)?

  • Matt O 0

    I forsee this spelling the end to all other SPA frameworks in existence! This is going to be awesome!

  • Peter Vunk 0

    Looking forward to start using Blazor 0.9!
    Already using Blazor 0.7 in internal production builds, with custom grid and custom drop down list, both are super easy to build using open source examples for Blazor 0.7! Web apps are stable and fast to load. Blazor is awesome! Saving me weeks of development time. Leaps and bounds ahead of React and Angular in terms of ease of learning, speed of development, and ease of customization! Keep up the excellent work!

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