Announcing .NET Core 3.1 Preview 1

Rich Lander [MSFT]

Today, we’re announcing .NET Core 3.1 Preview 1. .NET Core 3.1 will be a small release focused on key improvements in Blazor and Windows desktop, the two big additions in .NET Core 3.0. It will be a long term support (LTS) release with an expected final ship date of December 2019.

You can download .NET Core 3.1 Preview 1 on Windows, macOS, and Linux.

ASP.NET Core and EF Core are also releasing updates today.

Visual Studio 16.4 Preview 2 and is also releasing today. It is a recommended update to use .NET Core 3.1 Preview 1. Visual Studio 16.4 includes .NET Core 3.1, so just updating Visual Studio will give you both releases.


Known Issue: The Visual Studio 16.4 installer may uninstall the .NET Core 3.0 Runtime when it installs .NET Core 3.1. We recommend you re-in-install or repair the .NET Core 3.0 SDK in that case.


There are several targeted improvements planned for .NET Core 3.1. The following improvements are not available yet, but are expected in later previews.

In .NET Core 3.0, the .NET Core Desktop Runtime Installer (includes WPF and Windows Forms) does not install the .NET Core Runtime (includes CoreFX and CoreCLR) for you. We will be changing that, so that the Desktop Runtime installer is self-sufficient. The Runtime and Hosting Bundle, for server scenarios, already works this way.

C++/CLI was a promised component of the .NET Core 3.0 release. It was delivered, given that it is a required dependency of WPF, but a developer experience in Visual Studio and the SDK was missing. We will be delivering that experience with .NET Core 3.1 and Visual Studio 16.4. C++/CLI is only supported on Windows.

macOS 10.15 Catalina includes a new security requirement, that applications must be notarized. We will be satisfying these requirements for the .NET Core SDK, for .NET Core 3.1 and all other supported .NET Core releases. If you are using .NET Core to deliver macOS applications, we would appreciate working with you on notarization requirements.


The primary goal of .NET Core 3.1 is to polish the features and scenarios we delivered in .NET Core 3.0. .NET Core 3.1 will be a long term support (LTS) release, supported for at least 3 years.

Please install and test .NET Core 3.1 Preview 1 and give us feedback. It is not yet supported or recommended for use in production.

If you missed it, check out the .NET Core 3.0 announcement from last month.


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

  • Thomas De Wulf 0

    Well a rare UWP developer in the house here…. šŸ™‚ When will this be supported so I can upgrade my Nuget packages to .NET standard 2.1 in my UWP apps.

  • piotr olczyk 0

    I would like to ask about suport to USB?
    Is the assembly Windows.Devices.HumanInterfaceDevice, which is a part of Windows UWP Namespaces is supported by NET.Core 3.0?

  • Jenny anams 0

    Succeed! It could be one of the most useful blogs we have ever come across on the subject. Excellent info! Iā€™m also an expert in this topic so I can understand your effort very well. Thanks for the huge help.

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