Microsoft has rolled out Preview 2 of its upcoming .NET 11 development platform, bringing a new wave of performance enhancements and developer-focused improvements. The release, available since March 10, follows the first preview from February and moves the framework closer to its final release scheduled for November 2026.

Runtime-native async and cleaner debugging

One of the most notable advancements in Preview 2 is progress toward runtime-native asynchronous execution. Traditionally, the compiler generated extra state-machine classes to manage async methods. Now, the runtime itself handles suspension and resumption. This shift results in simpler stack traces, smoother debugging, and less overhead—though the feature remains in preview and must be explicitly enabled using MethodImplOptions.Async.

The runtime’s JIT compiler also sees smarter optimizations: it can now safely remove redundant array bounds checks and unnecessary operations in arithmetic contexts, improving performance across common coding patterns.

Smaller SDK installers for macOS and Linux

Developers on Linux and macOS will benefit from leaner SDK installers, achieved by deduplicating assemblies through symbolic links. Identical .dll and .exe files are hashed, matched, and replaced with symbolic links pointing to a single copy, trimming down the size of .tar, .pkg, .deb, and .rpm packages.

Smarter code analysis and diagnostics

In the .NET SDK, Microsoft refined its code analyzer to avoid wasteful logging. Routine method calls like GetHashCode(), GetTimestamp(), and property accesses are no longer flagged unnecessarily. Diagnostics now focus on “Information” level messages by default, cutting noise and helping developers target meaningful warnings. Additionally, new explanations in diagnostic messages clarify why a particular argument was flagged.

Expanded library support

.NET 11 libraries now include new overloads for TarFile.CreateFromDirectory, supporting the TarEntryFormat parameter. Developers can now specify one of four formats—Pax, Ustar, GNU, or V7—for better compatibility with different tools and build environments.

ASP.NET Core, F#, MAUI, and EF Core updates

• ASP.NET Core: The Kestrel web server now uses a non-throwing parsing path for malformed HTTP/1.1 requests. Instead of continuously raising exceptions, it returns a structured result that improves throughput by 20–40% under high error traffic.
• F#: Simplified Default Interface Member (DIM) hierarchies make the language cleaner, and a new preview feature caches overload resolution results to speed up repeated method calls.
• .NET MAUI: TypeConverter support for Location and MapSpan brings simpler XAML syntax for handling map coordinates, while TypedBinding and SourceGeneratedBinding are 29% faster and use 50% less memory per operation.
• Entity Framework Core: EF Core now supports translating MaxByAsync and MinByAsync LINQ methods (and their synchronous versions), enabling easier selection of elements with the highest or lowest keys.