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

Unifying API testing, API Performance testing, API Mocks and UI testing.

WebLOAD – Performance and Load Testing for the Most Challenging Web Applications

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.

Don’t just observe. Take action. The only app monitoring platform built for developers that gets to the root cause for every issue.

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