LoadFocus - Cloud Testing Infrastructure | Cloud Testing Services and Tools for Websites & APIs.
Postman - The Collaboration Platform for API Development
Loader.io - Loader.io is a simple cloud-based load testing service
Ping-API - Automated API testing and monitoring.
Loadster - Loadster is a full-featured load testing solution for websites, web apps, and web services.
HTTPie for Terminal - Developers all around the world rely on HTTPie for API testing.