# Selecting a Load And Performance Testing Framework - Gatling vs. Grafana k6 I just **got the task, to advise on which performance testing framework to use** for our product. As we already use [Grafana](https://grafana.com/), the suggestion coming from our Dev Lead, to examine whether it would be a good fit or not. As we are using [Karate DSL](https://github.com/karatelabs/karate) for API testing, a straightforward choice would be to go with [Gatling](https://gatling.io/), as it nicely integrates with Karate DSL, and we can reuse our existing tests for performance testing. I **compiled a list of important aspects to examine** when choosing a performance and load testing framework. I reused the list from my [Selenide vs. Selenium article](https://mszeles.com/selenium-or-selenide) and adapted it a little bit. I will use a simple scoring system but of course, again, you cannot simply decide based on the final score. - Skillset available in the company - Learning curve and ease of use - License cost - Integration with cloud testing services - Test case reusability - CI/CD integration - Detailed reports ## Skillset available in the company **Our team has experience with Karate DSL**. The t**est cases written with Karate DSL using the Gherkin language can be reused with Gatling** so Gatling seems to be a reasonable choice. [Grafana k6](https://k6.io/) requires JavaScript knowledge. Of course, our front-end developers are familiar with JavaScript, but our test automation engineers are not. So the standing is **Gatling:Grafana 1:0**. ## Learning curve and ease of use In order to use any load testing framework, **you have to be familiar with the theory of performance testing**, which is needed independently from the tool. I am planning to take the [ISTQB Performance Testing](https://www.istqb.org/certification-path-root/performance-testing.html) training and exam later this year. Having the theoretical background, **using Gatling is very simple,** thanks to the reusability of the existing test cases. As G**rafana k6 requires JavaScript** and **learning a new syntax for testing code**, it is one point again to Gatling. The standing is **Gatling: Grafana 2:0.** ## License cost ### Grafana k6 Grafana k6 has both a [**free**](https://k6.io/open-source/) **and a** [**paid version**](https://k6.io/pricing/). Grafana k6 itself is an open-source framework that you can use free of charge. The pricing of the cloud solution's Developer version is $99/month which allows 50 test runs monthly with a max duration of 15 mins, and it can only run on one thread. The pricing of the cloud solution's Team subscription is $499/month and it allows 75 runs per month, which I still consider very little. The max run duration is 30 mins and you can run your tests on 2 parallel threads. There is also a pro version for $1499/month which allows 100 test runs with a 60-minute time limit and 4 parallel threads. There is also an Enterprise version which has a custom price depending on your needs. ### Gatling Similarly, Gatling **has both a free and a paid version.** Gatling is also an [open-source framework](https://gatling.io/open-source/). For the paid version you have the option to use the [cloud service](https://gatling.io/pricing/), or a self-hosted version. The Scout cloud subscription costs 99€/month with a limit of 60 minutes test running duration and it has a 1-month data retention period. The Scale version costs 396€/month with a 24hours maximum test execution duration and 3-months data retention period. This version also comes with a CI/CD plugin. The Corporate version costs 1380€/month with more than 24 maximum test execution time and 6 months of data retention The self-hosted version starts from 4800€/year. However we won't use the cloud service in the short run, but we might use it in the long run. With the pricing of Gatling, it is a clear winner. **Gatling: Grafana k6 3:0.** ## Integration with cloud testing services This topic is the same as the one above, so the standing is still **Gatling:Grafana k6 3:0.** ## Test case reusability With **Grafana k6** we have to start** building our performance tests from scratch**, and with **Gatling**, **we can reuse our existing Karate DSL tests**, so it is a clear win again for Gatling. Standing is Gatling:Grafana k6 4:0. ## CI/CD integration **Grafana k6 can be integrated into your CI/D pipeline**, you can [find some instructions about it here](k6 Open Source). **Gatling free version can be also** [easily integrated into your CI/CD pipeline](https://gatling.io/features/load-testing-as-code-for-ci-cd-integration-automation/) and from the cloud version, it is available from The Scale subscription. This is a draw, so the standing is **5:1 for Gatling.** ## Detailed reports Both [Gatling](https://gatling.io/docs/gatling/reference/current/stats/reports/) and Grafana k6 have a detailed reporting with lots of useful charts. ## Conclusion It is a clear win for Gatling. So **for our team**, **I suggest using Gatling framework for performance testing.** **What is your number one performance testing framework? Please share your experiences in the comment section.** In case you do **not want to miss my posts**, just **follow me** [here on Hashnode](https://mszeles.com/), on [LinkedIn](https://www.linkedin.com/in/miklos-szeles/), on [Twitter](https://twitter.com/mszeles) on [Medium.com](https://medium.com/@mszeles), on [dev.to](https://dev.to/mszeles) and even on [Instagram](https://www.instagram.com/szelesmiki/). 😊 📚**Join the Selenide community** on [LinkedIn](https://www.linkedin.com/groups/9154550/)! ✌