Changes in YourKit .NET Profiler 2026.9

• Artificial intelligence
• macOS support
• Windows support
• Security
• User interface
• CPU profiling
• Thread profiling
• IDE integration
• Miscellaneous
• Deprecations

Artificial intelligence

• feature AI-assisted profiling is a major new feature in version 2026.9. The built-in MCP server enables AI tools and agents to analyze .NET application performance, identify bottlenecks, and investigate their causes.

  

• feature The profiler integrates with popular AI tools, including Antigravity, Claude, Codex, Copilot, Cursor, Junie, OpenCode, and VS Code. You can configure the integration using the setup wizard or the profiler CLI.

  

macOS support

• caveat We have raised the minimum supported macOS version. The profiler now requires macOS 15 or later.

Windows support

• feature The Windows installer now supports installing the profiler for the current user without administrator privileges. Previously, installation was only available for all users. Silent installation also supports the new /CurrentUser option.
• improvement The Windows installer now offers to uninstall previously installed major versions of the profiler, in addition to minor bug-fix builds.

Security

• improvement The OpenSSL library used by the YourKit agent has been updated to version 3.5.8.
• improvement The bundled version of Netty has been updated to 4.1.138.

User interface

• feature Support for installing multiple profiler versions side by side has been improved, along with settings migration during upgrades.

• feature Snapshots now load in the background without blocking the profiler UI, so you can continue working while another snapshot opens. Loading progress is also reported more accurately, especially during dominator calculation. These improvements are particularly useful when opening large snapshots, which can take a long time to load.

  

• feature The filter configuration dialog now includes a Revert to Default button that restores the default filter configuration. This makes it easy to recover default filters that have been deleted or incorrectly edited.

  

• improvement Double-clicking a column divider in a table now restores the default column width.
• fix An issue that could prevent the profiler from closing on exit has been fixed.

CPU profiling

• feature The Hot spots and Method list views from version 2026.3 have been redesigned and merged into a singleHot spots view. The new view displays all method metrics and eliminates the overlap between the two previous views.

  

• feature The Hot spots view is now available during live profiling with real-time updates, as well as in snapshots.
• feature The Hot spots view now includes Own time and Avg. time columns.
• feature A new toolbar button in the Hot spots view lets you filter out library methods independently of the global filters.
• improvement The Hot spots view now runs up to 3 times faster and no longer freezes the profiler during updates.

Thread profiling

• feature The Thread state column now displays the state name alongside the color icon, making thread states easier to identify without a tooltip.

  

IDE integration

• caveat The minimum supported version of Rider is now 2024.1.

Miscellaneous

• improvement The profiler's dependencies are now packaged as separate libraries in the lib directory instead of being bundled into a single fat yourkit.jar. This does not affect how the profiler or CLI tools are launched. The new layout makes it easier to inspect the software bill of materials (SBOM).
• improvement Bundled runtimes have been updated.

Deprecations

Deprecation means that we intend to remove the feature or capability from a future release of YourKit .NET Profiler. The feature or capability will continue to work and is fully supported until it is officially removed.

• The deprecated HTTP API v2 has been removed. Please use HTTP API v3.