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Grafana k6 documentation
This documentation will help you go from a total beginner to a seasoned k6 expert!
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What is k6?
Grafana k6 is an open-source load testing tool that makes performance testing easy and productive for engineering teams. k6 is free, developer-centric, and extensible.
Using k6, you can test the reliability and performance of your systems and catch performance regressions and problems earlier. k6 will help you to build resilient and performant applications that scale.
k6 is developed by Grafana Labs and the community.
Watch the video below to learn more about k6 and why it could be the missing puzzle in your Grafana stack.
Key features
k6 is packed with features, which you can learn all about in the documentation. Key features include:
- CLI tool with developer-friendly APIs.
- Scripting in JavaScript ES2015/ES6 - with support for local and remote modules
- Checks and Thresholds - for goal-oriented, automation-friendly load testing
Use cases
k6 users are typically Developers, QA Engineers, SDETs, and SREs. They use k6 for testing the performance and reliability of APIs, microservices, and websites. Common k6 use cases are:
Load testing
k6 is optimized for minimal resource consumption and designed for running high load tests (spike, stress, soak tests).
Browser testing
Through k6 browser, you can run browser-based performance testing and catch issues related to browsers only which can be skipped entirely from the protocol level.
Chaos and resilience testing
You can use k6 to simulate traffic as part of your chaos experiments, trigger them from your k6 tests or inject different types of faults in Kubernetes with xk6-disruptor.
Performance and synthetic monitoring
With k6, you can automate and schedule to trigger tests very frequently with a small load to continuously validate the performance and availability of your production environment.
Load Testing Manifesto
Our load testing manifesto is the result of having spent years hip deep in the trenches, doing performance- and load testing. We’ve created it to be used as guidance, helping you in getting your performance testing on the right track!
- Simple testing is better than no testing
- Load testing should be goal oriented
- Load testing by developers
- Developer experience is super important
- Load test in a pre-production environment
What k6 does not
k6 is a high-performing load testing tool, scriptable in JavaScript. The architectural design to have these capabilities brings some trade-offs:
Does not run natively in a browser
By default, k6 does not render web pages the same way a browser does. Browsers can consume significant system resources. Skipping the browser allows running more load within a single machine.
However, with k6 browser, you can interact with real browsers and collect frontend metrics as part of your k6 tests.
Does not run in NodeJS
JavaScript is not generally well suited for high performance. To achieve maximum performance, the tool itself is written in Go, embedding a JavaScript runtime allowing for easy test scripting.
If you want to import npm modules or libraries using NodeJS APIs, you can bundle npm modules with webpack and import them in your tests.