Deal with different language versions
As programming languages evolve, it is only natural to improve your code with new language features. On the other hand, there may be factors that prevent you from upgrading to the newest language version.
ReSharper is aware of different language versions. It analyzes code and applies its own features according to the current language version. Language version is detected automatically for each language, but you can set version manually for some of the languages as described below.
C#
ReSharper 2025.3 fully supports all C# versions up to C# 14.
ReSharper automatically detects and uses C# version specified in the project file *.csproj.
To change the version, open the project file in the editor and change the <LangVersion> attribute.
To set the C# version for all projects in your solution, specify it in a Directory.Build.props file in your solution directory as described here. Note that language versions defined in the .csproj files will override the versions specified in the Directory.Build.props file.
VB.NET
ReSharper 2025.3 fully supports all VB.NET versions up to VB 14 and partially VB 15.
ReSharper automatically detects and uses Visual Basic version specified in the project file *.vbproj.
To change the version, open the project file in the editor and change the <LangVersion> attribute.
TypeScript
When TypeScript support is explicitly enabled on the page of ReSharper options , ReSharper supports TypeScript language features from v. 1.4 to v. 3.0. ReSharper automatically detects TypeScript version by the <TypeScriptToolsVersion> property in the Visual Studio project file. But you can specify the target TypeScript version explicitly using the TypeScript language level selector on the page of ReSharper options .
JavaScript
When JavaScript support is explicitly enabled on the page of ReSharper options , ReSharper provides JavaScript support up to ECMAScript 2016, including experimental features such as async/await, exponentiation operator and rest/spread in object literals/destructuring. jQuery and JSX syntax are supported as well.
By default, code inspection and other ReSharper features analyze JavaScript code according to the ECMAScript 5 standard, which is supported universally. If you use more advanced JavaScript code in your project, you can change the target ECMAScript level on the page of ReSharper options .
C++
ReSharper 2025.3 supports C, C++/CLI, C++ up to C++20, and partially C++23. ReSharper detects C++ version automatically based on the platform toolset ( in the project properties) and/or on the /std switch.
CSS
When CSS support is explicitly enabled on the page of ReSharper options , ReSharper supports CSS up to version 4.0. In practical terms, CSS version is by far less important than CSS feature set supported by different web browsers. Therefore, ReSharper lets you tune its CSS code inspection for specific versions of particular web browsers. You can configure it on the options page.