What's new in .NET 9

Learn about the new features in .NET 9 and find links to further documentation.

.NET 9, the successor to .NET 8, has a special focus on cloud-native apps and performance. It will be supported for 18 months as a standard-term support (STS) release. You can download .NET 9 here.

New for .NET 9, the engineering team posts .NET 9 preview updates on GitHub Discussions. That's a great place to ask questions and provide feedback about the release.

This article has been updated for .NET 9 Preview 3.

.NET runtime

The .NET 9 runtime includes performance improvements, including faster exception handling, inlining improvements for Native AOT, and loop and PGO improvements. For more information, see What's new in the .NET 9 runtime.

.NET libraries

The .NET 9 libraries include improvements to serialization, cryptography, LINQ, reflection emit, and more. For more information, see What's new in the .NET 9 libraries.

.NET SDK

The .NET 9 SDK includes improvements to the terminal logger, tool roll-forward, and unit testing. For more information, see What's new in the SDK for .NET 9.

.NET Aspire

.NET Aspire is an opinionated, cloud-ready stack for building observable, production ready, distributed applications.‚Äč .NET Aspire is delivered through a collection of NuGet packages that handle specific cloud-native concerns, and is available in preview for .NET 9. For more information, see .NET Aspire (Preview).

ASP.NET Core

ASP.NET Core includes improvements to ... For more information, see What's new in ASP.NET Core 9.0.

.NET MAUI

.NET MAUI includes ... For more information, see What's new in .NET MAUI for .NET 9.

EF Core

Entity Framework Core includes improvements to ... For more information, see What's New in EF Core 9.

C# 13

C# 13 ships with the .NET 9 SDK. For more information, see What's new in C# 13.

See also