Gatling

Gatling is an open source load testing tool. Test scenarios, called simulations, are written as code in Java, JavaScript, TypeScript, Kotlin or Scala, run against the services under test, and produce a detailed HTML report of response times, throughput and errors.

Virtual users are lightweight messages on a non-blocking engine built on Netty rather than operating system threads, so a single machine can generate a high load. Because tests are code, they live in the project repository and follow the same review process as the application; they can run locally or in continuous integration and fail the build when performance regresses.

Gatling Community Edition is distributed under the Apache License 2.0 and is actively developed on GitHub; version 3.16.0 was released in September 2026. A commercial Enterprise Edition adds a managed platform with reporting, AI-assisted analysis and conversion of LoadRunner and JMeter scripts.