Scalene vs YourKit .NET Profiler

Scalene is a free, open-source profiler for Python programs that reports CPU, GPU and memory use and offers AI-powered optimization proposals. Its line- and function-level reports separate Python time from native-code and system time. Memory analysis shows per-line use, distinguishes Python from native allocations and flags lines with likely memory leaks. GPU profiling reports time on NVIDIA-based systems. Async profiling attributes wall-clock await time to the suspended coroutine line and reports mean and peak concurrent waiters. Its graphical interface can display stitched Python and native call stacks, memory flame charts and a timeline. Scalene is usable from the command line, a web-based GUI, a Visual Studio Code extension or Jupyter notebooks. The web interface processes profiles locally and works offline. For optimization suggestions, listed AI providers include Amazon Bedrock, Microsoft Azure, OpenAI and local models through Ollama. The project reports typical profiling overhead of no more than 10–20%, often less. Scalene is available for free under the Apache-2.0 license, with installations listed for macOS, Linux, Windows and Windows Subsystem for Linux 2.

YourKit.NET Profiler analyzes CPU performance and memory use in.NET and.NET Core applications. It can profile servers, Windows services, and other.NET applications locally or remotely in development, testing, and production. CPU results appear as call trees or hot spots; memory tools visualize the object heap and object graph. Plugins integrate with Microsoft Visual Studio and JetBrains Rider. The profiler shows slow SQL queries and ASPX requests and supports MongoDB and Cassandra. More than 20 inspections can identify duplicated objects, unclosed database connections, inefficient collections, and I/O operations. Remote profiling can create an SSH tunnel to an application on another machine. A.NET API manages profiling modes and captures snapshots, while command-line tools can automate profiling and performance monitoring in continuous integration. Version 2026.9 supports.NET 5 through.NET 10 and.NET Framework 4.x, with Linux, macOS, and Windows downloads. A single-seat annual subscription costs $99 a year; a perpetual single-seat license costs $129 as a one-time purchase. A 15-day trial is listed, and qualifying open source project contributors and Microsoft MVPs can contact sales regarding a free license.