Locust

Locust is an open-source, developer-friendly load testing framework that allows you to define user behavior in plain Python code. It's designed for testing web applications, APIs, and other systems, supporting hundreds of thousands of concurrent users through its event-based architecture. Locust offers a real-time web-based UI for monitoring and analysis, and is actively maintained with frequent updates (approximately every 62 days) [1, 2, 11, 19, 31]. It currently requires Python 3.10 or newer [31].