Locust vs k6: What are the differences?

Locust: Define user behaviour with Python code, and swarm your system with millions of simultaneous users. Locust is an easy-to-use, distributed, user load testing tool. Intended for load testing web sites (or other systems) and figuring out how many concurrent users a system can handle; k6: Developer centric open-source load and performance testing tool. It is a developer centric open source load testing tool for testing the performance of your backend infrastructure. It’s built with Go and JavaScript to integrate well into your development workflow.

Locust and k6 belong to "Load and Performance Testing" category of the tech stack.

Some of the features offered by Locust are:

• Define user behaviour in code
• Distributed & scalable
• Proven & battle tested

On the other hand, k6 provides the following key features:

• Written in Go and JavaScript, built to integrate well into the modern developer workflow and automation pipelines
• Primarily for load testing, it also works for functional testing of APIs and microservices with its powerful JS ES6 based scripting API
• Straightforward CLI, sharing many UX aspects with the DevOps tools you already use

Locust and k6 are both open source tools. Locust with 11.2K GitHub stars and 1.62K forks on GitHub appears to be more popular than k6 with 5.57K GitHub stars and 287 GitHub forks.