Performance testing needs tools that can simulate many virtual users and measure the system's response. There is a healthy mix of open-source and commercial options; here are the ones teams reach for most.
Apache JMeter — our preferred open-source tool
JMeter is a mature, free, open-source performance testing tool, and our recommended starting point. It can load-test web applications, APIs, databases, and more, with a graphical interface for building test plans and a powerful command-line mode for CI/CD. Its huge community, plugin ecosystem, and zero licence cost make it an outstanding default choice.
- Free and open source, with a large community.
- Supports web, API, database, and more.
- GUI for building plans, CLI for automated runs.
- Rich plugins and integrations.
Other notable tools
| Tool | Type | Notes |
|---|---|---|
| JMeter | Open source | Our preferred all-rounder |
| k6 | Open source | Developer-friendly, scripts in JavaScript |
| Gatling | Open source | Code-based (Scala), great reports |
| LoadRunner | Commercial | Enterprise-grade, broad protocol support |
| Locust | Open source | Python-based, easy to script |
k6 is loved by developers for its scriptable, modern approach. Gatling produces excellent reports. LoadRunner remains a powerful enterprise option with wide protocol support, at a commercial cost.
Conclusion
There is a strong field of performance tools, but JMeter is our preferred open-source choice for its capability, community, and zero cost. k6, Gatling, and LoadRunner each have their place depending on your team's skills and budget.