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

All-in-one observability. New Relic Dashboard Video Tour Video Tour Data for engineers to monitor, debug, and improve their entire stack.

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

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.

Status, performance and uptime monitoring for cron jobs, websites, APIs and more.

Uptime Kuma is an easy-to-use self-hosted monitoring tool.