ReSharper 2025.3: Day-One C# 14 Support, Visual Studio 2026 Compatibility, and Major Performance Gains

Sasha Ivanova

We’re pleased to announce the release of ReSharper 2025.3 in sync with .NET 10, continuing our tradition of releases that deliver day-one support for the newest C# language features.

This version brings comprehensive C# 14 coverage, including extension members, extension operators, and user-defined compound assignment operators – all ready to use as soon as you download the latest .NET SDK.

Alongside the language updates, ReSharper 2025.3 introduces substantial performance improvements in both In-Process and Out-of-Process modes, resulting in faster startup, smoother interaction with Visual Studio, and dramatically improved solution-wide analysis responsiveness.

Same-day comprehensive support for C# 14 

ReSharper 2025.3 finalizes support for C# 14 extensions, now including extension operators alongside extension methods and properties. All relevant refactorings – such as Change Signature, Convert Method to Property, Make Static, and Safe Delete – have been updated to handle extension members correctly.

New inspections, quick-fixes, and context actions introduced in 2025.3 will also make it easier to switch between traditional extension methods and the new syntax when refactoring existing code.

Other ReSharper features have been extended to support these new member types, including:

• Usage analysis that detects and highlights unused extension members.
• Import completion now supports additional scenarios, such as object initializers and pattern matching.
• Optimize usings now correctly recognizes directives required by new extension members.
• Call hierarchy and value tracking allow for accurate exploration of call graphs and data flow involving extensions.

Learn all there is to know about C# 14 support in ReSharper and Rider 2025.3 from this blog post.

Performance improvements

Startup and shutdown

ReSharper 2025.3 delivers faster startup and shutdown in In-Process mode, with internal testing showing:

• ~15% faster startup and full solution load times.
• ~50% fewer UI unresponsiveness periods.
• Shutdown time reduced by 66%, from 30 seconds to 10 seconds.

Out-of-Process mode

ReSharper continues to refine Out-of-Process (OOP) mode, improving its stability and responsiveness in Visual Studio. OOP mode remains off by default but can be enabled via Options | Environment | Products & Features → Run ReSharper in separate process.

Find Usages and Solution-wide analysis

Performance improvements also extend to Find Usages in C#. We’ve optimized its handling of language injections, introduced targeted caching, and fine-tuned internal logic. Since Find Usages powers many refactorings, such as Rename and Change Signature, these actions now execute faster.

Solution-wide analysis (SWA) now becomes available sooner after opening a solution, while keeping Visual Studio more responsive during startup.

ReSharper Build

ReSharper Build is the default tool used in JetBrains Rider and can also be enabled in ReSharper. It allows for faster build times by avoiding the building of dependencies that don’t need to be rebuilt. Unlike MSBuild, ReSharper Build is aware of the managed assemblies and their public surface – if, after your changes, the public surface of the assembly remains unchanged, the dependent projects (without changes) do not need to be built.

In 2025.3, we replaced the assembly surface hashing algorithm with a faster, almost allocation-less one, which is powered by Microsoft’s System.Reflection.Metadata library. For large solutions, this new algorithm significantly reduces memory allocation during the build process, resulting in gigabytes less memory being consumed. This means the IDE will build the solution slightly faster (less time spent on hashing) and feel snappier during and after the build is completed (much less allocated memory for garbage collection to handle).

The new algorithm is enabled by default and works completely transparently. In the case of problems, you can switch to the old one:

Compatibility with Visual Studio 2026

ReSharper 2025.3 is expected to be fully compatible with Visual Studio 2026. 

Learn how to migrate ReSharper to the latest version of Visual Studio here.

C++ Support

ReSharper C++ 2025.3 advances C++26 support, adding features such as pack indexing, expansion statements, packs in structured bindings, and contracts.

For more C++ updates from the latest release, see this blog post.

Miscellaneous

ReSharper on Open VSX

ReSharper for VS Code is now listed on the Open VSX Registry, allowing developers using Cursor, Windsurf, VSCodium, and other VS Code–compatible editors to install and receive automatic updates – no more manual .vsix downloads.

The TeamCity extension returns

Based on user feedback, the TeamCity extension is back and included once again in the dotUltimate installer. We appreciate everyone who shared how crucial this integration is for their CI workflows.

Command-line tools

The InspectCode command-line tool now supports writing results directly to standard output with the --stdout option, simplifying CI/CD integration and automation.

dotTrace, dotMemory, dotCover, and dotPeek 

For this release cycle, our efforts on JetBrains .NET tools have focused on bug fixes, stability improvements, and a range of minor enhancements across all four tools to ensure a smoother and more reliable experience.

Tell us what you think

We’d love to hear your feedback on ReSharper 2025.3! Let us know how these updates work for your projects in the comments below or reach out to us on X and Bluesky.

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