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.

Loader.io is a free load testing service that allows you to stress test your web-apps & apis with thousands of concurrent connections.

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

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.

Cloud-scale performance testing. Effortless load testing and synthetic checks at scale. Cloud-native and open-source. The next evolution of performance testing.

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