Microsoft released .NET 10 in November 2025, and .NET 11 Preview 1 followed in February 2026. If you’re making platform decisions right now (whether you’re modernizing legacy code, starting a greenfield project, or planning your next upgrade cycle), you’re probably asking the same question everyone else is: do I stay on .NET 10 or plan for .NET 11?
The answer depends on your timeline, your risk tolerance, and what specific capabilities you need. This post gives you the facts to make that call.
Before comparing features, the single most important difference between .NET 10 and .NET 11 is their support model.
|
|
.NET 10 |
.NET 11 |
|
Release Date |
November 11, 2025 |
Expected November 2026 |
|
Support Type |
LTS (Long Term Support) |
STS (Standard Term Support) |
|
Support Duration |
3 years → November 2028 |
2 years → November 2028 |
|
C# Version |
C# 14 |
C# 15 |
|
Visual Studio |
VS 2026 (required) |
VS 2026 Insiders (for now) |
|
Production Ready? |
Yes. GA since Nov 2025 |
No. Preview only |
Notice the support end dates: both .NET 10 and .NET 11 are scheduled to lose support around the same time (November 2028), though .NET 10 gets there with a year’s head start of production stability. Teams that adopt .NET 11 at GA will have the same support runway as teams already running .NET 10, but without the year of production battle-testing.
Based on Preview 1 (with more features expected through the preview cycle), here’s what .NET 11 introduces that .NET 10 doesn’t have:
.NET 10: Async/await works the way it has since C# 5. The compiler rewrites every async method into a state machine struct, hoists local variables to heap-allocated fields, and generates IL the runtime executes without understanding its async semantics.
.NET 11: The runtime itself now understands async methods as a first-class concept. The compiler emits simpler IL, and the runtime takes over responsibility for suspending, resuming, and optimizing async execution. CoreCLR support is enabled by default. Early results show roughly 50% less memory allocation in common async patterns, plus dramatically cleaner stack traces during debugging.
Why it matters: This is the most architecturally significant change in .NET’s async infrastructure in over a decade. For applications with heavy async workloads (e.g. APIs, data pipelines, microservices), this translates to measurable performance improvement without code changes.
.NET 10: Blazor WebAssembly runs on the Mono runtime, which has known performance limitations and doesn’t benefit from CoreCLR’s optimization investment.
.NET 11: Foundational work begins to bring CoreCLR to WebAssembly, including a WASM-targeting RyuJIT for AOT compilation. This is explicitly not ready for production in Preview 1. Full support is targeted for .NET 12, but the migration off Mono has started.
Why it matters: If Blazor WebAssembly is in your modernization roadmap, this signals a serious long-term investment. CoreCLR on WASM means faster execution, JIT capabilities, and consistent behavior whether your .NET code runs on a server, desktop, or browser.
.NET 10: No built-in Zstd support. Teams needing Zstandard compression rely on third-party NuGet packages.
.NET 11: Introduces ZstandardStream as a first-class compression API in the BCL. No external dependencies required.
.NET 10: Built the AI story around the Microsoft Agent Framework, Microsoft.Extensions.AI abstractions, and MCP protocol support, focused on integrating AI services into .NET applications.
.NET 11: Adds BFloat16, a hardware-friendly floating-point type optimized for machine learning inference workloads. This is lower-level than .NET 10’s AI integration layer. It’s about making .NET itself more efficient for numeric AI computation.
.NET 10: Runs on the same hardware baseline as .NET 8 and .NET 9.
.NET 11: Raises the minimum x86/x64 baseline from x86-64-v1 to x86-64-v2 (requiring SSE4.2, POPCNT, etc.) and updates ReadyToRun targets to x86-64-v3 (AVX2, FMA). Arm64 on Windows now requires LSE. Applications will fail to launch on non-compliant hardware.
Why it matters: Most modern hardware meets these requirements (the last non-compliant CPUs lost vendor support around 2013), but if you’re running on older on-premises servers, this is a blocker. Verify before committing to .NET 11.
.NET 10 delivered: Blazor WebAssembly preloading, automatic memory pool eviction in Kestrel, passkey authentication, OpenAPI 3.1 with YAML support, QuickGrid RowClass for conditional styling, and improved form validation.
.NET 11 adds: EnvironmentBoundary component for conditional rendering, IHostedService support in Blazor WebAssembly (background services in the browser), QuickGrid OnRowClick events, relative navigation with RelativeToCurrentUri, IOutputCachePolicyProvider for dynamic cache resolution, and auto-trust of dev certificates in WSL.
.NET 10 (C# 14): Field-backed properties, extension properties, the nameof expression for unbound generics, enhanced overload resolution, and ref struct interfaces for allocation-free patterns. A substantial language release.
.NET 11 (C# 15): Preview 1 includes only Collection Expression Arguments so far. More features are expected in later previews, but the language story is still thin at this stage.
.NET 10 (EF Core 10): Vector search for AI workloads (semantic search, RAG), native JSON data type support for SQL Server 2025, full-text search functions, left/right join operators, and custom default constraint naming.
.NET 11 (EF Core 11): Complex types and JSON columns on entity types with TPT/TPC inheritance, plus one-step migration creation and application.
.NET 10: Global XAML namespaces, compile-time XAML generation, updated platform bindings, and extended control capabilities.
.NET 11: XAML source generation by default (builds on .NET 10’s work), and CoreCLR replaces Mono as the default Android runtime in release builds.
Since .NET 11 builds on top of .NET 10, all of .NET 10’s capabilities carry forward. This includes:
In other words, .NET 11 isn’t a replacement for .NET 10. It’s .NET 10 plus a focused set of runtime, library, and tooling additions. You’re not giving anything up by starting on .NET 10 today and upgrading later.
Here’s the timeline that should drive your decisions:
|
Version |
Released |
End of Support |
Time Left |
|
.NET 8 (LTS) |
Nov 2023 |
Nov 10, 2026 |
≈8 months |
|
.NET 9 (STS) |
Nov 2024 |
Nov 10, 2026 |
≈8 months |
|
.NET 10 (LTS) |
Nov 2025 |
Nov 2028 |
≈2.5 years |
|
.NET 11 (STS) |
Nov 2026 (est.) |
Nov 2028 (est.) |
Not yet released |
The critical takeaway: .NET 8 and .NET 9 both hit end of support on the same day, November 10, 2026. After that date, no security patches, no bug fixes, no compliance updates from Microsoft. Whether you chose .NET 8 for stability or .NET 9 for features, the clock runs out simultaneously.
At GAPVelocity AI, our VELO modernization platform currently targets .NET 10 for production migrations. It’s the right target for the vast majority of teams modernizing legacy applications—stable, fully supported, and feature-rich.
We’re actively evaluating .NET 11’s Runtime Async capabilities for our own platform internals, because the performance characteristics of the async code VELO generates during migration will benefit directly from these runtime improvements. When .NET 11 reaches GA in November 2026, we expect to offer it as a migration target option for teams whose workloads and upgrade cadence support STS adoption.
Here’s the simple version:
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Your Situation |
Our Advice |
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On .NET 6 or earlier |
You’re out of support. Migrate to .NET 10 immediately. |
|
On .NET 8 |
Plan your .NET 10 migration for Q2 2026. Don’t skip to .NET 11. It won’t be GA in time. |
|
On .NET 9 |
Easy hop to .NET 10. Do it now. It’s the smallest migration you’ll ever do. |
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On .NET 10 |
You’re good through 2028. Evaluate .NET 11 after GA for workloads that benefit from Runtime Async. |
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Modernizing legacy code |
Target .NET 10 today. Upgrade to .NET 11 or 12 later. Never chase a preview as a migration target. |
|
Greenfield project (late 2026) |
Start on .NET 10. Retarget to .NET 11 at GA if the features justify it. |
The .NET ecosystem moves fast. But a good platform decision isn’t about chasing the newest version. It’s about choosing the version that matches your timeline, your team’s capacity, and your application’s needs. For most teams today, that answer is .NET 10.
Planning a migration and need to nail your target framework? GAPVelocity AI’s VELO platform delivers 85–95% automated code coverage for legacy-to-modern .NET migrations, with AI Squads handling the last mile.