StresStimulus - Load testing tool for websites and mobile that works with hard-to-test applications.
Loader.io - Loader.io is a simple cloud-based load testing service
LoadComplete - The only load testing tool to record, replay, and test in real browsers at scale.
k6 Cloud - Managed load testing service built on top of the popular open-source project k6.
Apache JMeter - Apache JMeter™.
SmartMeter.io - Performance Testing with Enterprise-Level Features with a familiar jMeter interface