Orderly Ape is an open source (MIT) tool to run distributed and scalable k6 load tests on your own infrastructure using k6, kubernetes, grafana and influxdb.

k6 Open Source is designed for load testing. Extensible to support other types of testing.

Hoppscotch is an open-source API development ecosystem that helps you create and test your API requests saving precious time in development.

The Apache JMeter™ application is open source software, a 100% pure Java application designed to load test functional behavior and measure performance. It was originally designed for testing Web Applications but has since expanded to other test functions.

Gatling is a powerful open-source load testing solution that integrates with your development pipeline. It includes a web recorder and colorful reports.

Bruno is a Fast and Git-Friendly Opensource API client, aimed at revolutionizing the status quo represented by Postman, Insomnia and similar tools out there.