Gatling review

Curator verified · Hands-on
Load Testing Open Source Self-hosted REVIEWED general pick

The short version

Gatling is the code-first option with the best built-in HTML report.

Simulations in Java, Kotlin, or Scala compile, so mistakes surface before a run, and the asynchronous engine sustains high concurrency on one machine. The open-source edition stops at single-node execution and HTTP plus a few protocols; distribution, live dashboards, and team features sit behind Gatling Enterprise. Choose it when a JVM team wants typed, reviewable load tests.

Strong
Scripting & extensibility, Reporting & analysis, CI/CD & automation
Adequate
Protocol coverage, Scale & distribution, Cost & licensing
Limited
AI features
Best for
Your team already writes Java, Kotlin, or Scala
License
Open Source
Pricing
Free open-source core; commercial platform available.
Deployment
Self-hosted
Scripting / languages
Java, Scala, Kotlin
First release
2012

Gatling review: the full verdict

Hands-on

What Gatling is

Gatling is a JVM load testing tool built on an asynchronous, non-blocking engine. You write a simulation in Java, Kotlin, or Scala using a typed DSL, compile it, and run it from Maven, Gradle, or sbt. There are also JavaScript and TypeScript SDKs now, which lowers the entry barrier for non-JVM developers, but the JVM path is still the mature one.

The company behind it sells Gatling Enterprise, and the split between the two editions is the thing to understand before you commit: the open source edition is excellent on one machine, and everything about running on many machines and watching results live sits in the paid tier.

In practice

If you are comfortable in Java or Kotlin, the DSL reads naturally: a scenario is a chain of exec calls with checks, feeders supply test data, and injection profiles describe how users arrive. Because the simulation compiles, a typo in a JSON path or a wrong parameter fails before the load run starts, not fifteen minutes into it. I appreciate this every time I come back from JMeter, where the same mistake shows up as a red sampler in the results tree.

The HTML report generated at the end of a run is, in my opinion, the best default report in the open source field. Response time percentiles, active users over time, and per-request breakdowns are all there without standing up Grafana. Throughput per injector is also very high thanks to the async engine.

Where it falls short

The open source edition is single node only. When one injector is not enough, you either script your own orchestration across machines and merge simulation logs by hand, or you buy Enterprise. Protocol support covers HTTP, WebSocket, SSE, JMS, MQTT, and gRPC; there is no JDBC sampler and nothing for legacy enterprise stacks. The Scala heritage still leaks into documentation and stack traces, and the compile step slows down the edit and run loop compared with k6 or Locust. Enterprise pricing is quote based, so budgeting takes a sales call.

AI features

Neither edition offers AI-assisted authoring or analysis today. Given how strong the typed DSL is, I do not consider that a blocker, but if AI-generated scripts are on your roadmap, this is a gap to note.

Bottom line: Gatling is the right pick when a Java or Kotlin team wants typed, reviewable load tests and a polished report without extra infrastructure. Plan for Enterprise if you need distributed runs, and look elsewhere if your testers do not code.

Scorecard

Qualitative, 7 dimensions

Strong, Adequate, or Limited on each dimension. No numeric scores and no averaging, because a Limited rating on the one dimension you depend on outweighs any total.

Scripting & extensibility STRONG Typed DSL in Java, Kotlin, Scala, plus JavaScript and TypeScript SDKs.
Protocol coverage ADEQUATE HTTP, WebSocket, SSE, JMS, MQTT, gRPC; no JDBC or enterprise protocols.
Scale & distribution ADEQUATE Very efficient per node, but multi-node orchestration is Enterprise only.
Reporting & analysis STRONG Best default HTML report in the open-source field.
CI/CD & automation STRONG Maven, Gradle, and sbt plugins with assertion-based exit codes.
Cost & licensing ADEQUATE Apache 2.0 core; distribution and dashboards require a paid tier.
AI features LIMITED No AI-assisted authoring or analysis in either edition today.

How we rate: methodology. Ratings are refreshed with each hands-on pass, not on a fixed schedule.

Pros & cons

What stood out during testing, and what got in the way.

Pros

  • Typed simulations catch errors before load runs
  • Excellent HTML report out of the box
  • High throughput per injector from the async engine
  • Recorder helps bootstrap HTTP scenarios

Cons

  • Open-source edition is single-node only
  • Scala heritage still shows in docs and stack traces
  • Slower iteration loop because simulations compile
  • Enterprise pricing is quote-based

Who it's for

A ten-second answer for teams shortlisting tools.

Pick Gatling when

  • Your team already writes Java, Kotlin, or Scala
  • You want a polished HTML report with no extra services
  • Compile-time checking of test code matters

Skip Gatling when

  • You need distributed runs without buying Enterprise
  • Non-JVM developers will maintain the tests
  • Protocols beyond HTTP, WebSocket, JMS, or MQTT are required

Getting started

Minutes to first script
$ Download the bundle or use the Maven/Gradle plugin
$ ./mvnw gatling:test

A day for JVM developers; steeper for testers without programming background.

Review FAQ

Answer-shaped
Is Gatling worth it in 2026?

Gatling is the code-first option with the best built-in HTML report. Simulations in Java, Kotlin, or Scala compile, so mistakes surface before a run, and the asynchronous engine sustains high concurrency on one machine. Your team already writes Java, Kotlin, or Scala

When should you pick Gatling?

Your team already writes Java, Kotlin, or Scala You want a polished HTML report with no extra services Compile-time checking of test code matters Together, these are the clearest signals that Gatling fits the project. Compare the current documentation, operating model, and total cost with the project requirements before making a final decision.

When should you skip Gatling?

You need distributed runs without buying Enterprise Non-JVM developers will maintain the tests Protocols beyond HTTP, WebSocket, JMS, or MQTT are required Treat these constraints as reasons to compare alternatives before committing to Gatling. Compare the current documentation, operating model, and total cost with the project requirements before making a final decision.

Does Gatling have AI features?

No AI-assisted authoring or analysis in either edition today. Check the current product documentation before relying on these capabilities in production. Compare the current documentation, operating model, and total cost with the project requirements before making a final decision.