.NET 10 is an LTS (Long Term Support) release: it receives updates and security fixes for three years. For business applications it is the natural foundation for upcoming projects.

Main new features

• C# 14: extension members, the field keyword, null-conditional assignment and implicit conversions to Span.
• Performance: the JIT optimises loops and virtual calls better and can stack-allocate small objects that do not escape the method.
• File-based apps: a single .cs file runs with dotnet run, no project needed.
• Security: post-quantum cryptography algorithms such as ML-KEM and ML-DSA.
• ASP.NET Core 10: validation in Minimal APIs, OpenAPI 3.1, passkeys in Identity, Blazor improvements.
• EF Core 10: LeftJoin and RightJoin operators, named query filters, vector search on SQL Server.

How to upgrade a project

In most cases you only need to change the target framework and update packages to version 10:

<PropertyGroup>
  <TargetFramework>net10.0</TargetFramework>
  <Nullable>enable</Nullable>
  <ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>

After upgrading, build with warnings enabled, read the breaking-change notes and run the full test suite. Libraries that depend on third-party packages must be checked one by one: that is where surprises hide.

When to migrate

If you are on .NET 8, which is also LTS, you have time to plan calmly. If you are on releases that are no longer supported, migrating to .NET 10 is the safest choice: a single jump and three years of support ahead.