.NET 5 to 10: Key Features Introduced in Every Release

Every November, .NET Conf brings a new major release of .NET. If you have been building on the platform since the early 2020s, you have watched the ecosystem move from “.NET Core” to a single, unified .NET — and pick up minimal APIs, Native AOT, Blazor full stack, Aspire, and a steady stream of C# language improvements along the way.

This post is a guided tour of what landed in each major version from .NET 5 through .NET 10. It is not exhaustive — Microsoft ships hundreds of changes per release — but it should help you remember which version introduced what, and where to dig deeper.

For the full release schedule and patch versions, see the official .NET releases documentation.

.NET 5 — November 2020

.NET 5 was the first release after the “Core” branding was dropped. Version 4.x was skipped deliberately so nobody confused it with .NET Framework 4.x. The message was clear: this is the main implementation of .NET going forward, not a side project.

Platform and runtime

• Unified vision — one BCL and runtime targeting cloud, desktop, web, mobile, and IoT (the full unification completed in .NET 6).
• Single-file applications and improved app trimming for smaller deployments.
• ClickOnce publishing for .NET (Windows).
• ARM64 support on Windows.
• Performance work across the runtime, GC, and networking stack.

C# 9

C# 9 shipped alongside .NET 5 and brought several features that are now everyday tools:

• Records — reference types with value-based equality and with expressions for non-destructive mutation.
• Init-only setters — immutable object initialisation without verbose constructors.
• Top-level statements — less boilerplate in small console apps.
• Pattern matching — relational patterns (>, <, and, or, not) and improved switch expressions.
• Source generators — compile-time code generation (the foundation for later JSON and logging generators).

Libraries and frameworks

• EF Core 5 — split queries, table-per-entity (TPE) mapping, and Cosmos DB improvements.
• ASP.NET Core in the 5.x line — gRPC improvements, HTTP/2 and HTTP/3 groundwork, and Blazor WebAssembly performance gains.
• System.Text.Json — constructor and parameterised constructor support, [JsonIgnore] on properties, and better options for ignoring cycles.

.NET 5 reached end of support in May 2022. If you still have projects on it, plan an upgrade — there are no security patches.

.NET 6 — November 2021 (LTS)

.NET 6 delivered on the unification promise: one SDK, one base class library, and one runtime across mobile, desktop, IoT, and cloud. It was an LTS release and became the baseline many teams standardised on.

Developer experience

• Hot reload in Visual Studio 2022 and dotnet watch — edit code and see changes without a full restart.
• Minimal APIs — build HTTP APIs with far less ceremony than traditional controllers.
• SDK workloads — optional components (MAUI, Blazor WebAssembly AOT, and others) install via dotnet workload instead of bloating the default SDK.
• Project templates modernised — top-level statements, file-scoped namespaces, nullable reference types, and async Main in new projects.

C# 10

• global using directives
• File-scoped namespaces
• Record structs
• Improved interpolated strings and constant interpolated strings
• AsyncMethodBuilder attribute for custom async method builders

Runtime and libraries

• DateOnly and TimeOnly — separate date and time types without carrying a full DateTime.
• PriorityQueue<TElement, TPriority> — a built-in min-heap.
• System.Text.Json source generator, writeable JsonNode DOM, and IAsyncEnumerable serialisation.
• HTTP/3 preview support via QUIC.
• OpenTelemetry metrics APIs in System.Diagnostics.Metrics.
• FileStream rewrite for better async performance on Windows.
• Arm64 support for macOS (“Apple Silicon”) and Windows, with side-by-side x64 and Arm64 installs.

ASP.NET Core 6

• Minimal APIs as a first-class style for microservices.
• Blazor components renderable from JavaScript; AOT compilation for Blazor WebAssembly.
• Improved gRPC and SignalR performance.

.NET MAUI

.NET Multi-platform App UI arrived in preview with .NET 6 — one codebase for Android, iOS, macOS, and Windows native apps. GA followed in 2022.

.NET 6 LTS ended in November 2024.

.NET 7 — November 2022

.NET 7 was a standard-term support release focused heavily on performance, cloud-native patterns, and polishing the developer experience. I wrote about upgrading to .NET 7 at the time — mostly smooth, with a few surprises around AutoMapper and EF Core triggers.

C# 11

• Raw string literals — multi-line strings without escape-character pain.
• required members — enforce initialisation at compile time.
• Generic math — static abstract interface members for numeric generics.
• List patterns — if (list is [var first, .., var last]).
• UTF-8 string literals — u8 suffix for byte-oriented APIs.

ASP.NET Core 7

• Rate limiting middleware — built-in protection against abuse.
• Output caching — cache entire responses at the framework level.
• Minimal API improvements — route groups, typed results, and filters.
• Native AOT for console apps — smaller, faster-starting binaries (ASP.NET Core AOT came in .NET 8).

Performance and tooling

• Continued JIT and GC improvements; Native AOT publishing matured.
• Regex source generator for compile-time pattern compilation.
• Library multi-targeting and package validation tooling for NuGet authors.

.NET 7 reached end of support in May 2024.

.NET 8 — November 2023 (LTS)

.NET 8 is the current-generation LTS baseline for many production workloads (supported until November 2026). It is the release where cloud-native tooling, Native AOT for web apps, and modern C# really clicked together.

C# 12

• Primary constructors — declare constructor parameters on the type declaration.
• Collection expressions — [1, 2, 3] syntax for arrays, spans, and lists.
• Alias any type — using Point = (int X, int Y);
• Default lambda parameters — optional parameters in lambdas.

ASP.NET Core 8

• Blazor full stack — server-side rendering, streaming rendering, and enhanced interactivity models in one framework.
• Native AOT for ASP.NET Core — ahead-of-time compilation for web workloads.
• Keyed dependency injection — register and resolve multiple implementations of the same interface by key.
• Frozen collections — optimised read-only collections for hot paths.
• TimeProvider — abstract time for testable code.

.NET Aspire (now just called Aspire)

.NET Aspire launched in preview with .NET 8 — an opinionated stack for observable, distributed applications. AppHost orchestrates dependencies; ServiceDefaults wire up OpenTelemetry, health checks, and resilience. I have been using it for local microservice development and it removes a lot of port-and-connection-string drudgery. In 2025 .Net Aspire was rebranded to Aspire and version 13 was released (don’t ask why 13, but I believe it was so it was no longer tied to .NET releases)

Other highlights

• EF Core 8 — complex types, primitive collections, JSON column mapping, HierarchyId.
• NuGet Audit — warnings when packages have known vulnerabilities.
• Windows Forms and WPF improvements — DPI, data binding, and hardware acceleration.
• Source generators for COM interop and configuration binding.

.NET 9 — November 2024

.NET 9 continued the annual cadence with performance, AI integration, and polish across the stack. I covered several highlights in my .NET 9 post when it shipped.

C# 13

• params collections — params works with Span<T>, ReadOnlySpan<T>, and collection types beyond arrays.
• lock on System.Object — the lock statement can use more types safely.
• Partial properties and indexers — split declarations across files.
• Escape sequence \e for the ESC character.

Platform and libraries

• Performance — runtime, GC, and JIT improvements across the board; the team publishes detailed benchmark posts each release.
• AI abstractions — Microsoft.Extensions.AI packages unify access to language models and embeddings from different providers.
• NuGet Audit defaults to reporting transitive dependency vulnerabilities (opt back to direct-only with <NuGetAuditMode>direct</NuGetAuditMode>).
• OpenTelemetry enhancements and better observability defaults.

ASP.NET Core 9 and Blazor

• MapStaticAssets() — fingerprinted, cache-friendly static files replace UseStaticFiles() for Blazor and modern web apps.
• Blazor component state persistence, improved form handling, and better WebAssembly performance.
• .NET Aspire 9 — dashboard improvements, deployment tooling, and more community integrations.

.NET 9 is standard-term support until November 2026.

.NET 10 — November 2025 (LTS)

.NET 10 is the current LTS release (supported until November 2028). If you are choosing a version for a new project in 2026, this is the long-term bet.

C# 14

• Field-backed properties — use the field keyword when you outgrow auto-properties.
• nameof for unbound generics — e.g. nameof(List<>).
• Implicit Span<T> conversions — less ceremony at API boundaries.
• ref/out/in in lambdas without explicit parameter types.
• Extension blocks — static extension methods and properties in a dedicated syntax.
• Null-conditional assignment (?.=) and user-defined compound assignment operators.

Runtime and libraries

• JIT improvements — better inlining, devirtualisation, and loop inversion.
• AVX10.2 support for SIMD workloads.
• Native AOT enhancements and improved struct argument code generation.
• JSON — stricter serialisation options, PipeReader support, duplicate property handling.
• Post-quantum cryptography — expanded ML-DSA and related APIs.
• WebSocketStream — simpler WebSocket usage; TLS 1.3 on macOS clients.

SDK and tooling

• dotnet test integrates Microsoft.Testing.Platform.
• Container images from console apps without a separate Dockerfile in simple scenarios.
• dotnet tool exec for one-shot tool runs.
• Native shell tab-completion scripts for the CLI.

ASP.NET Core 10 and Blazor

• Blazor WebAssembly preloading and automatic memory pool eviction.
• Passkey support for ASP.NET Core Identity.
• OpenAPI and minimal API improvements.

One breaking change caught me when upgrading a Blazor WebAssembly app: HttpClient response streaming is enabled by default, which broke synchronous Stream.Read calls in generated API clients. I wrote about the fix in Blazor and .NET 10 — either opt out with <WasmEnableStreamingResponse>false</WasmEnableStreamingResponse> or move to async reads.

EF Core 10, MAUI, and desktop

• EF Core 10 — named query filters, Cosmos DB improvements, and LINQ performance work.
• .NET MAUI 10 — multi-file MediaPicker, WebView interception, Android API 35/36 support.
• Windows Forms and WPF — continued quality and Fluent-style updates.

How to choose a version in 2026

Microsoft’s guidance has shifted over the years: LTS releases (6, 8, 10) alternate with STS releases (5, 7, 9) on an annual November cadence. STS now lasts two years; LTS lasts three. Remember there is no difference in quality between a LTS and STS release, it is only the support window that is different.

Further reading

• .NET download
• What’s new in each .NET version — official docs
• C# language version history
• My earlier posts: Upgrading to .NET 7 , .NET 9 , Blazor and .NET 10 , and Getting started with Aspire

If you have been on the platform since .NET 5, you have lived through the best decade of .NET since the original framework shipped.