Gatling

With Gatling, your entire load testing strategy becomes code you control: flexible, versioned, and endlessly customizable. Design every aspect of your load tests using Gatling’s powerful SDKs for Java, Scala, Kotlin, JavaScript, and TypeScript.

Gatling’s asynchronous, event-driven architecture can simulate millions of users while using a fraction of the CPU and memory of traditional thread-per-user tools. This efficiency translates directly into lower infrastructure costs: you can run the same tests with fewer machines, or push to higher concurrency without blowing up your budget.