.NET 10: What You Need to Know in 2026

Release and Support

.NET 10 is the next major release of Microsoft’s unified .NET platform (successor to .NET 9). It was released in November 2025 and is an even-numbered (LTS) release. Even-numbered .NET versions ship in November with Long-Term Support (3 years), while odd-numbered versions get 2-year support. As an LTS release, .NET 10 will be supported until late 2028, making it recommended for enterprise and production use. In fact, Microsoft specifically advises that production applications upgrade to .NET 10 to benefit from its extended support window, performance gains, and new capabilities. 

The annual cadence (November each year) is now predictable: .NET 10 arrives 12 months after .NET 9, and will be followed by .NET 11 in November 2026.

Performance and Runtime Improvements

One of the defining highlights of .NET 10 is its focus on raw performance and runtime efficiency. Microsoft describes it as “the fastest .NET yet”, and this claim is backed by meaningful improvements across the runtime, compiler, and hardware acceleration layers.

At the core, .NET 10 introduces significant runtime optimizations, including enhanced JIT compiler capabilities such as improved method inlining, loop inversion, and more aggressive devirtualization. These changes allow frequently executed code paths to run faster with fewer instructions. Stack allocation has also been expanded, enabling small arrays and temporary data structures to be allocated on the stack rather than the heap, reducing garbage collection pressure and improving memory locality.

.NET 10 further strengthens its ahead-of-time compilation story with improved NativeAOT support, producing smaller binaries and faster startup times, particularly valuable for cloud-native and serverless workloads. These enhancements make .NET applications more competitive in performance-sensitive environments.

On the hardware side, .NET 10 adds first-class support for modern CPU capabilities, including Intel AVX10.2 instructions and ARM SVE vectorization, along with improved write barriers for advanced memory handling. These features enable better use of modern processors, delivering measurable gains in throughput and reduced memory usage across real-world workloads.

Practical optimizations—such as faster array enumeration and improved devirtualization in hot paths—have been validated through community benchmarks and detailed performance analyses, including deep dives by Stephen Toub. For enterprise architects and CTOs focused on scalability, responsiveness, and infrastructure efficiency, these runtime improvements make .NET 10 a compelling upgrade.

Language Updates: C# 14, F# 10, and Visual Basic

.NET 10 ships alongside major updates to its supported languages, continuing the platform’s emphasis on developer productivity, safety, and expressiveness.

C# 14

C# 14 introduces a wide range of new syntax and compiler features aimed at reducing boilerplate and improving code clarity. Notable additions include field-backed properties, which allow automatic backing fields while still supporting custom logic using the field keyword, and extension properties and methods, enabled through new extension blocks.

The language also adds nullable-conditional assignment (?.=), implicit Span<T> conversions, support for unbound generics in nameof, and the ability to use parameter modifiers (ref, in, out) in lambdas without explicit type annotations. Additional enhancements include partial events and constructors, user-defined compound assignment operators (+=, -=), and custom increment/decrement operators (++, --).
Collectively, these features make C# 14 more expressive while maintaining its strong focus on safety and performance—reinforcing its position as one of the world’s most widely used and trusted programming languages.

F# 10

F# 10 is a refinement-focused release that improves performance, tooling, and language ergonomics. .NET Developers can opt into preview features using <LangVersion>preview</LangVersion>, while the updated SDK automatically applies the latest FSharp.Core library improvements.
Key enhancements include finer-grained control over compiler warnings, access modifiers for auto-properties, ValueOption parameters for heap-free optional values, and improved tail-call support in computation expressions. Build performance has also been improved through better parallel compilation and trimming, resulting in faster builds and smaller application footprints.

Visual Basic

Visual Basic in .NET 10 receives targeted but important upgrades. The compiler now fully supports the unmanaged generic constraint, improving interoperability with low-level and performance-oriented APIs. It also respects overload-resolution priority attributes, ensuring that Span-based overloads are preferred where appropriate. These changes allow VB developers to take advantage of modern .NET runtime and library improvements without friction.

Library Enhancements

The .NET 10 base class libraries add many new APIs for security, globalization, serialization, and more. Important highlights:

• Cryptography and security: Expanded post-quantum cryptography (PQC) support. .NET 10 adds Windows CNG APIs for ML-DSA and ML-KEM algorithms, an enhanced ML-DSA variant (HashML-DSA), and Composite ML-DSA hybrids for defense-in-depth. It also introduces AES KeyWrap with Padding for secure key wrapping. These changes help future-proof apps against quantum threats while remaining compatible with existing code.
• Networking and APIs: New and modernized networking features: a simplified WebSocketStream API makes WebSockets easier to use and more efficient. TLS 1.3 support has been added for macOS clients (bringing macOS in line with other platforms). Windows process management gains process group support for better isolation of signals and child processes. Across the board, HTTP, socket, and WebSocket layers have reduced allocations and higher throughput.
• JSON and serialization: The System.Text.Json serializer now lets you disallow duplicate JSON properties and offers stricter default settings for safer deserialization. It also supports reading from a PipeReader for high-performance scenarios. Additional serialization enhancements include new collection types and options in APIs.
• Collections and utilities: Perf improvements in ZipArchive (only load needed entries into memory), numeric string comparison via CompareOptions.NumericOrdering, new overloads (e.g. TimeSpan.FromMilliseconds(int64)), and ISOWeek methods for the new DateOnly type. An AOT-safe constructor was added to ValidationContext. OrderedDictionary<TKey,TValue> gets a new TryAdd(key, value, out index) method. These library tweaks improve performance and developer convenience.

Globalization and Text: String normalization helpers for spans (IsNormalized, TryNormalize) and collation improvements are included. These speed up common text tasks without extra allocations.

ASP.NET Core 10 and Web API

.NET 10’s web stack (ASP.NET Core 10.0) brings many enhancements for building web apps and APIs:

• Blazor improvements: Faster loading and runtime for Blazor WebAssembly (including preloaders, memory pool eviction, QuickGrid styling, etc). Better integration for Blazor Hybrid in MAUI (mobile + web) and new profiling tools for Blazor WASM.
• Minimal APIs: Validation is now first-class. You can call AddValidation() to wire up DataAnnotations or custom validation for minimal APIs. Optional parameters and better JSON options simplify creating microservices and quick endpoints. Performance and troubleshooting for minimal APIs continue to improve.
• OpenAPI/Swagger: Full support for OpenAPI/Swagger v3.1 is new. Now you can export OpenAPI docs in YAML as well as JSON. OpenAPI generation can now use JsonNode types instead of low-level OpenAPI-specific classes, simplifying doc generation. These make API documentation much easier for enterprise teams.
• SignalR and Real-Time: While not a headline, SignalR sees improved performance and lower latency. New support for Server-Sent Events (SSE) in ASP.NET Core 10 makes pushing updates (dashboards, live notifications, etc.) simpler without full WebSockets overhead.
• Forms and Validation: ASP.NET Core 10 treats empty form fields as null for nullable types, avoiding many manual checks. Form validation attributes ([ValidatableType]) and AddValidation() make model binding more robust. Together these reduce boilerplate in web UI code.

Cross-cutting: ASP.NET Core 10 also adds features like Passkey (FIDO2) support in Identity, enhanced diagnostics, and JSON schema upgrades. In summary, web developers get more productivity and security out of the box. (An industry article notes that ASP.NET Core 10 has “more powerful and flexible” minimal APIs and Blazor, plus built-in metrics for auth events.)

.NET SDK and Tooling

The .NET 10 SDK itself gets many CLI and productivity boosts:

• Command-line (CLI) enhancements: dotnet test now integrates the new Microsoft Testing Platform for unified test execution. The CLI auto-generates native tab-completion scripts for shells (bash, PowerShell, zsh, etc.). You can publish file-based apps natively (see below) and create container images for console apps without writing Dockerfiles. A new dnx exec script and dotnet tool exec command allow one-shot tool execution. The --cli-schema option exposes the CLI schema for introspection. The SDK now supports platform-specific tools (with multiple RuntimeIdentifiers) and a new SLNX solution file format (XML, simpler to edit). All these improve developer workflows on the command line.
• File-based Apps: .NET 10 introduces file-based applications. You can now build and run apps from a single C# file (like a script) without an explicit .csproj. Directives (e.g. #:package, #:property) in the file specify dependencies, frameworks, and AOT settings. This is ideal for small utilities and quick prototypes: the SDK auto-generates the project and even enables native AOT publishing by default. For example, dotnet run tool.cs will compile and run tool.cs as a complete app. File-based apps can also be packaged as global tools. In practice, this eliminates boilerplate for scripts and micro-apps, letting teams prototype faster.
• Containers and Images: Building container images is smoother. Any console app can now natively create a container image using dotnet publish p: PublishProfile=Container, without hand-written Dockerfiles. You can choose image formats explicitly. This eases cloud container deployments in enterprise pipelines.
• Testing and NuGet: dotnet test improvements and built-in Live Unit Testing continue in Visual Studio 2026 (see below). NuGet gets better security: it audits transitive dependencies by default, connects to the GitHub advisory database, and supports Dependabot updates. You can now run dotnet package update --vulnerable to auto-update all vulnerable packages. NuGet.org also has a refreshed UI. These changes strengthen the supply chain for .NET projects.
• Tooling: Visual Studio 2026 and the C# Dev Kit (VS Code) have been updated for .NET 10. VS 2026 adds better startup (faster solution load) and C#14 support. The C# Dev Kit for VS Code bundles refactorings and QA tooling for .NET 10. GitHub’s IntelliCode and Azure integrations are tighter. Teams using JetBrains Rider or VS Code will find .NET 10 toolchains well-supported.

Cross-Platform and Frameworks

.NET 10 continues the “write once, run anywhere” vision across desktop, mobile, and cloud:

• .NET MAUI and Mobile: MAUI 10 gains quality improvements: the MediaPicker control now supports selecting multiple images and compressing them, WebViews can intercept requests, and Android API level 35/36 are supported. These refinements make cross-platform mobile/desktop apps more robust.
• Entity Framework Core 10: EF Core 10 adds several data-layer upgrades: LINQ query enhancements and performance optimizations, improved Azure Cosmos DB support, and named query filters (you can define multiple filters per entity and enable/disable them selectively). These features help developers write cleaner data access code.
• Windows UI (WinForms/WPF): Desktop UI frameworks continue to evolve. WinForms .NET 10 includes clipboard-related fixes, quality improvements, and it brings in the legacy .NET Framework UITypeEditor classes for better designer support. WPF .NET 10 focuses on performance tweaks and new Fluent design styles, along with bug fixes. These ensure existing desktop apps modernize smoothly.
• Containers and Cloud: .NET 10 is fully supported on Linux/Windows/Mac. It adds TLS 1.3 on macOS and Docker image support, as noted. Azure integrations (Azure SDK clients) are updated to leverage .NET 10 features. For example, .NET 10’s improved networking and security directly benefit cloud services.

Developer Productivity and AI Integration. 

Beyond raw performance, .NET 10 emphasizes developer productivity and modern workloads. Its unified platform spans full-stack scenarios (web, cloud, desktop, mobile, AI). Key aspects:

• Unified AI APIs: Microsoft is pushing .NET as a first-class AI platform. .NET 10 includes new Microsoft.Extensions.AI libraries and templates for building AI-powered apps and multi-agent systems. While in-depth AI frameworks (like the Microsoft Agent Framework and Model Context Protocol support) are beyond this summary, it’s noteworthy that .NET 10 makes it easier to integrate services like OpenAI, semantic kernel, and custom AI workflows with consistent APIs. Enterprise apps can leverage these for features like chatbots or intelligent agents.
• Observability and Cloud-Native: .NET 10 co-evolves with Azure and cloud best practices. There are built-in extensions for telemetry (OpenTelemetry support) and distributed tracing. New tooling (e.g. the --cli-schema introspection) helps with automation. The Aspire framework (for microservices orchestration) is updated to v13.1 with .NET 10, providing out-of-the-box telemetry, service discovery, and resilience patterns.
• Rich Community and Ecosystem: The .NET ecosystem is large: over 478,000 NuGet packages and many corporate users trust .NET (Xbox, Bing, Azure, Teams, etc.). .NET 10’s enhancements (performance, security, language productivity) reflect community feedback. The release notes and docs are open on GitHub for contributions. For developers and architects, this means .NET 10 is a solid, well-supported platform backed by a thriving community.

Adoption and Migration

Should you upgrade to .NET 10? If you need long-term stability and the latest features, the answer is yes. As an LTS release, .NET 10 is ideal for new projects and for companies planning a migration roadmap. Existing .NET 6/8 applications can generally move to .NET 10 with minimal code changes (standard APIs remain largely backward-compatible).

The official guidance is: stay current on the latest patch to qualify for support, then upgrade major versions in a planned way. For migrating from older .NET Framework or .NET Core, there are tools and step-by-step guides (see Microsoft docs and community guides) – the key is testing your app on .NET 10 SDK and fixing any obsoleted APIs or platform differences.

In Summary

.NET 10 is a huge step forward for the .NET platform – it combines aggressive performance tuning with productivity enhancements and modern APIs. It delivers “hundreds of features and bug fixes across the entire stack”. Enterprise architects and CTOs should note its LTS support, hardware-accelerated runtime, and enriched libraries (especially around security and AI). Hobbyists and developers will enjoy the new language sugar (C# 14), streamlined app models (file-based apps), and improved web/devops tooling. In short, .NET 10 is designed to be forward-thinking and future-proof – it’s ready for the next generation of AI-enabled, cloud-native applications. Upgrading sooner can yield better app performance and security, and it aligns you with Microsoft’s long-term .NET roadmap.