k6 is an open-source load testing tool where tests are written as JavaScript code and run on a fast Go engine. It is a good fit for performance checks inside CI pipelines and stress testing APIs before a launch.

Yes. k6 is open source under the AGPL-3.0 licence. Its source code is on GitHub at grafana/k6 and is written mainly in Go.

Yes. k6 is open source, so the software itself is free to use. A managed cloud version is also available, with paid plans from $25,000 per year.

What is k6 an alternative to?

k6 is an open-source alternative to OpenText LoadRunner, BlazeMeter and loader.io. Other open-source alternatives to OpenText LoadRunner include Locust, Artillery and Apache JMeter.

Is k6 actively maintained?

Yes. The most recent commit to k6 was on 2 October 2026, and the latest release is v2.3.0, published on 21 September 2026. The project has 32k stars on GitHub.

k6: open-source alternative to OpenText LoadRunner

About k6

k6 is a load-testing tool for developers and testers, described as unit testing for performance. Test scripts are written in JavaScript and executed by an embedded engine written in Go, combining scripting familiarity with efficient load generation. It is maintained under the Grafana organization and released under the AGPL-3.0 license.

Because tests are code, scripts can be modularized, version controlled and run from the command line, in CI or across a Kubernetes cluster. k6 supports HTTP, WebSockets, gRPC and browser protocols, and an extension ecosystem adds more. Results can be summarized or exported as granular metrics to the service of your choice, and the tool integrates natively with Grafana Cloud for test execution and analysis. For people who prefer not to write code, k6 Studio is a desktop app that generates scripts.

Key features

Load tests written as JavaScript code
Go engine for efficient traffic generation
HTTP, WebSocket, gRPC and browser protocols
Extension ecosystem for added capabilities
Flexible metrics export to other services
k6 Studio desktop app for no-code scripts

Good fit for

→Performance checks inside CI pipelines
→Stress testing APIs before a launch

Built with: Go; JavaScript
Tags: load-testing; performance; javascript; golang; devops; ci; grafana; api-testing

k6: questions and answers

What is k6 used for?: k6 is an open-source load testing tool where tests are written as JavaScript code and run on a fast Go engine. It is a good fit for performance checks inside CI pipelines and stress testing APIs before a launch.
Is k6 open source?: Yes. k6 is open source under the AGPL-3.0 licence. Its source code is on GitHub at grafana/k6 and is written mainly in Go.
Is k6 free?: Yes. k6 is open source, so the software itself is free to use. A managed cloud version is also available, with paid plans from $25,000 per year.
What is k6 an alternative to?: k6 is an open-source alternative to OpenText LoadRunner, BlazeMeter and loader.io. Other open-source alternatives to OpenText LoadRunner include Locust, Artillery and Apache JMeter.
Is k6 actively maintained?: Yes. The most recent commit to k6 was on 2 October 2026, and the latest release is v2.3.0, published on 21 September 2026. The project has 32k stars on GitHub.