Loader

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

Similar Tools

Performance testing with Flood increases customer satisfaction and confidence in your production apps and reduces business risk.
Comprehensive and user-friendly cloud platform for Load Testing, Speed Testing and Website & API Optimization and Monitoring
k6
k6 Open Source is designed for load testing. Extensible to support other types of testing.
The Complete Continuous Testing Platform Any test. Any device. App quality without limits.
Anyone on your team can load test with instant playback, an easy-to-use interface, and real browsers for reliable data.
WebLOAD – Performance and Load Testing for the Most Challenging Web Applications