🧠 The short answer most teams need
If you are starting a new application today, use .NET 10.
It is the current Long Term Support release and will be supported until November 2028. That alone makes it the safest default.
If you are maintaining an existing production system, your safest choices right now are .NET 10 or .NET 8. Both are supported, but .NET 8 has a much shorter runway left.
If you are considering .NET 9, do it intentionally. It is a Short Term Support release and only makes sense if your team is comfortable upgrading again soon.
📅 Supported .NET versions right now
| .NET Version | Support Type | End of Support |
|---|
| .NET 10 | LTS | November 2028 |
| .NET 9 | STS | November 2026 |
| .NET 8 | LTS | November 2026 |
This table explains almost every decision you need to make.
🧩 LTS vs STS explained like a human
LTS is what you choose when stability matters more than chasing the newest features. LTS releases are supported for about three years and are ideal for business applications, enterprise systems, and long-lived products.
STS is for teams that like moving fast and upgrading often. STS releases are supported for a shorter time and assume you will move to the next version on schedule.
Most problems happen when teams choose STS but behave like they chose LTS.
🏗️ Which .NET version should you use based on what you’re building
🚀 New applications
Use .NET 10. It gives you the longest support window, modern performance improvements, and a clean baseline for future upgrades. Starting new projects on older versions usually creates unnecessary work later.
🧱 Existing applications on .NET 8
If your app is already on .NET 8, you are not in trouble, but the clock is ticking. Support ends in November 2026. If your dependencies allow it and your test coverage is reasonable, upgrading to .NET 10 sooner rather than later usually reduces future pain.
⚡ Existing applications on .NET 9
Treat .NET 9 as a temporary stop, not a destination. It is fine if you knowingly chose STS, but you should already have a plan to move to .NET 10 well before 2026 ends.
🧯 Applications on .NET 6 or .NET 7
These versions are already out of support. Running out-of-support frameworks is not just a security concern. Over time, tooling, hosting providers, and third-party libraries quietly move on, and your upgrade becomes harder and more expensive. If possible, jump straight to .NET 10. If not, use .NET 8 as a short-term bridge.
🪟 .NET Framework applications
If you are on .NET Framework, your decision is different. For Windows-only legacy systems with heavy dependencies, staying put for now may be realistic. For anything that needs cloud deployment, containers, cross-platform support, or modern performance, you should plan a gradual migration to modern .NET.
🎯 A decision framework that actually works
Is this a new app meant to live for years? Use .NET 10.
Do you want the least maintenance and longest support? Use .NET 10 LTS.
Are you blocked by dependencies or vendors? Use .NET 8 temporarily and plan your move to .NET 10.
Are you intentionally upgrading every one to two years? Then .NET 9 can make sense.
🛠️ Locking your team to the right version
Check installed SDKs.
dotnet --list-sdks
dotnet --list-runtimes
Pin the SDK using global.json to avoid environment drift.
{"sdk": {
"version": "10.0.100",
"rollForward": "latestFeature"}}
Target the correct framework.
<PropertyGroup>
<TargetFramework>net10.0</TargetFramework>
</PropertyGroup>
For shared libraries.
<PropertyGroup>
<TargetFrameworks>net8.0;net10.0</TargetFrameworks>
</PropertyGroup>
🔄 A low-risk upgrade strategy
Upgrade the SDK and build pipeline first without changing the target framework. This separates tooling issues from runtime issues.
Update NuGet packages early because most upgrade problems come from outdated dependencies.
Avoid mixing framework upgrades with large refactors so rollbacks stay cheap.
Measure before and after. Startup time, memory usage, throughput, and latency should guide decisions, not assumptions.
⚠️ Common mistakes teams keep making
Choosing STS for long-lived systems and forgetting to upgrade.
Staying on unsupported versions because nothing is broken yet.
Upgrading without pinning the SDK and wasting time debugging environment differences.
🧾 Final recommendation
If you want one boring, correct answer, use .NET 10.
It gives you the longest support window, aligns with Microsoft’s direction, and minimizes forced upgrades.
Use .NET 8 only as a short-term step if you are blocked.
Use .NET 9 only if you are disciplined about upgrading again.
❓ Top 5 FAQs: Choosing the Right .NET Version
1. Should I still start a new project on .NET 8?
Only if you have a hard dependency that does not yet support .NET 10. Otherwise, .NET 10 is the better long-term choice.
2. Is .NET 9 safe for production?
Yes, but only if you treat it as short-term. The risk is not stability, it is forgetting to upgrade later.
3. How often should I upgrade .NET in production apps?
Most teams should upgrade every LTS cycle, roughly every three years. STS requires a faster and more disciplined cadence.
4. Can I skip versions when upgrading .NET?
In most cases, yes. Many teams move directly from .NET 6 or 7 to .NET 10 as long as dependencies are compatible.
5. Does upgrading .NET automatically improve performance?
Often, but not magically. Real gains come when you upgrade, test, measure, and remove old workarounds that newer runtimes no longer need.