Microsoft .NET Framework version 6, a long-term support (LTS) release launched in November 2021, is nearing the end of its official support period. On November 12, 2024, Microsoft will cease support for this version, urging developers to transition their applications to .NET 8 to ensure continued access to security updates and official support.
Rahul Bhandari, a program manager with the Microsoft .NET team, highlighted the importance of upgrading from .NET 6, explaining that while applications built on this version will still function beyond the end-of-support date, they will become vulnerable to security threats as patches will only be available for supported versions.
.NET 6 has a typical LTS lifecycle of three years. In contrast, non-LTS releases like .NET 7 are supported for just 18 months, with support extending six months past the release of the subsequent LTS version. This staggered release strategy allows Microsoft to deliver major .NET versions annually, alternating between LTS and non-LTS versions.
As the latest LTS release, .NET 8 is set to be supported until November 2026. Developers currently using .NET 6 can upgrade to either .NET 8 or the upcoming .NET 9, a non-LTS version scheduled for release in November 2024. It's worth noting that support for .NET 7 has already ended as of May 2024.
Upgrading to .NET 8 is generally straightforward, requiring only a minor modification in the project file to target the new framework version. However, developers should know potential runtime or source-code incompatibilities between .NET 6 and .NET 8. To assist with the transition, Microsoft offers an open-source upgrade tool called "upgrade-assistant," which analyzes application code, updates project files, and checks for breaking changes. Although the tool can automate some fixes, developers may still need to address specific issues manually.
The developer community has expressed mixed reactions to the frequent release schedule. Some developers argue that the quick pace and short overlap between supported versions can be challenging. In contrast, others believe the upgrade process, which takes about a day every two years, is manageable.
According to telemetry data from May 2024, .NET 6 remains the most widely used version, accounting for 39% of the installed applications, followed by .NET 8, which has 26% of installations.