Loadster - Loadster is a full-featured load testing solution for websites, web apps, and web services.
Loader.io - Loader.io is a simple cloud-based load testing service
LoadFocus - Cloud Testing Infrastructure | Cloud Testing Services and Tools for Websites & APIs.
Loadium - Performance Testing & Load Testing Tool
HailStorm - Simple Integration and Load Testing Tool using Java 11
LoadForge - Better, cheaper load testing for websites, APIs and servers