Rider 2025.3: Day-One Support for .NET 10 and C# 14, a New Default UI, and Faster Startup

Sasha Ivanova

Rider 2025.3 arrives alongside the .NET 10 SDK, continuing our commitment to day-one support for the latest .NET and C# features.

This release brings full compatibility with .NET 10 and comprehensive support for C# 14, including extension members, extension operators, and user-defined compound assignment operators – all ready to use from the moment you upgrade your SDK.

In addition to same-day language support, Rider 2025.3 introduces the Islands theme as the new default UI, delivers substantial startup and responsiveness improvements, and expands its game development toolset for Unity, Unreal Engine, and Godot.

Same-day support for the .NET 10 SDK

Rider 2025.3 offers full compatibility with .NET 10 projects from day one. This means you can:

• Create, run, and debug projects targeting the new SDK.
• Use project templates targeting .NET 10.
• Take advantage of all C# 14 language enhancements.

Comprehensive C# 14 support

Rider 2025.3 brings complete, compiler-aligned support for C# 14, extending and refining the IDE’s understanding of new language constructs. 

Extension members and operators

• Full support has been added for extension members, now including extension operators in addition to methods and properties.
• All key refactorings – Change Signature, Convert Method to Property, Make Static, and Safe Delete – work seamlessly with extension members.
• Code analysis and exploration features, such as usage analysis, import completion, optimize usings, call hierarchy, and value tracking, now fully recognize extension members.
• New inspections and quick-fixes help you migrate between traditional extension methods and the new syntax.

General C# 14 updates

• Support has been added for user-defined compound assignment operators, with code analysis, completion, and refactoring support.
• The field keyword’s behavior has been updated to match the latest C# 14 compiler implementation, ensuring consistent analysis and highlighting.
• A new inspection warns about potential breaking changes when using Enumerable.Reverse with spans, helping you identify subtle runtime differences.

For a deeper look at our C# 14 support, see the blog post detailing the latest updates to C# support in Rider and ReSharper 2025.3.

New default UI theme: Islands

Rider 2025.3 introduces the Islands theme as the new default option across JetBrains IDEs.
Initially released in early 2025, the Islands theme offers a modern aesthetic with a clearer visual hierarchy between the editor and tool windows, improved tab visibility, and balanced light and dark modes that reduce visual clutter.

If you prefer the classic look, you can switch themes at any time via Settings | Appearance & Behavior | Appearance.

Performance improvements and startup optimizations

Rider 2025.3 delivers a smoother and faster startup experience. Several internal initialization phases have been optimized, reducing total solution load time and making core IDE features available sooner.

The main performance improvements of this release include:

• The editor no longer flickers during startup.
• Code completion, search, and navigation become available earlier.
• Unreal Engine projects now load up to 20 % faster and use less memory when scanning and caching assets.

What’s been fixed

In addition to the new features, this release resolves a wide range of issues reported by the community, improving Rider’s stability and reliability. 

See the full list of fixes in our dedicated What’s Been Fixed in Rider 2025.3 post.

ASP.NET and database issue detection in the Monitoring tool window

The Monitoring tool window in Rider 2025.3 has evolved into a single hub for real-time performance insights. It now detects new types of performance issues in database operations and ASP.NET Core applications – functionality that was previously available only in the Dynamic Program Analysis (DPA) tool window is now fully integrated into Monitoring.

Read this blog post to learn more.

Perforce MCP support for version control

Through our partnership with Perforce, Rider now offers built-in support for the Perforce MCP Server, simplifying setup and activation directly from the IDE. The integration extends to JetBrains AI Assistant, allowing it to access Perforce data in order to provide more contextually relevant answers.

Learn how to configure the Perforce MCP server here.

Game development

Unity

The IL Viewer tool window now displays the intermediate language (IL) code of assemblies actually used by Unity after post-processing, offering deeper insight into your compiled output.

Unreal Engine

• You can now debug Unreal Engine Android builds, view full call stacks, and deploy and debug directly to Android devices. Please note: At this stage, Android mobile development is supported only for .uproject models; .sln projects are not yet compatible.
• constexpr debugging support lets you pause execution inside constexpr functions and inspect variables as you would in regular runtime debugging.
• Additionally, you can switch from .sln to .uproject files directly in Solution Explorer for smoother navigation.

Godot

• Rider 2025.3 further enhances its Godot integration with more accurate handling of nested classes and enums, refined inspections for unused parameters, and support for typed Dictionary structures.
• You can now debug specific scenes and tool scripts, pass arguments to debug sessions, and start new projects from a GDExtension template.
• The IDE also integrates with the Chickensoft GoDotTest runner and keeps the Godot Inspector in sync by automatically rebuilding projects when focus leaves the IDE.

Working with native code

Rider 2025.3 introduces syntax highlighting for inactive preprocessor branches, so keywords and identifiers remain colorized for better readability even when disabled.

Detailed data sharing

The detailed data collection option in JetBrains IDEs, initially announced earlier this year, has been delayed to version 2025.3.1 as we work to incorporate your feedback. Among other things, we’re improving safeguards and streamlining the opt-out process for non-commercial users. Read the original blog post.

As always, you will find the full overview of enhancements included in the release on our website’s What’s New in Rider 2025.3 page and the full list of resolved issues on our issue tracker.

Tell us what you think

We hope you enjoy the new capabilities in Rider 2025.3!
Let us know how these updates affect your workflow – share your thoughts in the comments below or reach out to us on X or Bluesky.

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