Today, we are excited to announce the fourth preview release of .NET 11! This release includes improvements across the .NET Runtime, SDK, libraries, ASP.NET Core, .NET MAUI, C#, Entity Framework Core, and more. Check out the linked release notes below and get started today.
This release contains the following improvements.
📚Libraries
- Process gets the biggest update in years
- Span-based Deflate, ZLib, and GZip encoder/decoder APIs
- Floating-point hex formatting and parsing
- System.Text.Json improvements
- See all library updates
⏱️Runtime
- Runtime libraries are now compiled with runtime-async
- JIT optimizations
- Hardware intrinsics and code generation
- See all runtime updates
🛠️ SDK
dotnet watchadds device selection for .NET MAUI and mobile projects- Fish shell completions match Bash, Zsh, and PowerShell
dotnet referenceand similar commands fall back to the current directory- OpenTelemetry replaces Application Insights for CLI telemetry
- See all SDK updates
C#
- Clearer diagnostic for misplaced
#!shebang directives - Opt-in compilation cache for the VBCSCompiler build server
- See all C# updates
🌐 ASP.NET Core
- HTTP QUERY in generated OpenAPI documents
SupplyParameterFromTempDatafor Blazor- Server-initiated Blazor Server circuit pause
- MCP Server template ships with the .NET SDK
- See all ASP.NET Core updates
📱 .NET MAUI
🎁 Entity Framework Core
- Approximate vector search for SQL Server 2025
- JSON mapping is fully integrated into the relational model
- Temporal period properties can map to CLR properties
dotnet efreads defaults fromdotnet-ef.json- See all EF Core updates
🚀 Get started
To get started with .NET 11, install the .NET 11 SDK.
If you’re on Windows using Visual Studio, we recommend installing the latest Visual Studio 2026 Insiders. You can also use Visual Studio Code and the C# Dev Kit extension with .NET 11.
I only care about the features and performance of WinForms, and I don’t care about anything else. Where can I check the improvements and feature updates related to WinForms?
In which version is compiler support (VS and Rider) for .NET 11 expected to be released?
What was the reason to put the dotnet-ef.json into its own directory?
It feels off sice all the other files (global.json, dotnet-tools.json, .editorconfig, etc.) don’t need that.
Why isn’t it there with the others?
I see you are working on System.Threading.RateLimiting, please add support of TimeProvider there!
Is there any measurable performance improve with the Runtime Async fully enabled ?
I saw this micro benchmark recently: https://github.com/MuratDincc/dotnetkonf26-async-demo
For 10M awaits (.NET 10 → .NET 11 with runtime-async=on)
– Time: 80 ms → 32 ms
– Heap allocated: 687 MB → 94 KB
Short answer: we still need to enable it in our benchmarks.
Long answer: Locally, when I hand-enable runtime-async for a variety of code paths and work around a number of known bugs, I see benefits in a number of benchmarks. DecompressAsync, for example, goes down to zero additional allocations when backed by an in-memory stream like MemoryStream.
However, I have a personal rule: perf results aren’t real until you see them in the lab. So until the whole benchmark suite is ready, I’m not willing to report anything.