Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

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

Anyone on your team can load test with instant playback, an easy-to-use interface, and real browsers for reliable data.

Test the Performance of Your Website Under Load

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

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