Generate HTML Reports With Grafana K6: A Comprehensive Guide

Oct 23, 2025 by Jhon Lennon 61 views

Grafana k6 HTML Report: A Comprehensive Guide

Hey guys! Ever wondered how to make your load testing results not only informative but also super easy to share and understand? Well, you're in the right place! This guide dives deep into generating HTML reports using Grafana k6, turning raw data into actionable insights. Let's get started!

Why HTML Reports?

Before we jump into the "how," let's quickly cover the "why." HTML reports offer several advantages over other formats:

Readability: HTML reports are designed to be easily read and understood by anyone, regardless of their technical background. This is crucial when sharing results with stakeholders who might not be familiar with command-line outputs or specialized data formats. Imagine trying to explain the complexities of your load test to your manager using a wall of text from your terminal. An HTML report, with its charts, graphs, and summary statistics, makes that conversation much smoother and more effective. It transforms abstract data into a tangible and accessible form. Think of it as translating technical jargon into plain English (or your preferred language!). By providing a clear and concise overview of the test results, HTML reports facilitate better decision-making and faster problem-solving.
Shareability: Sharing an HTML report is as simple as sending a file. No special software or configuration is needed – just a web browser! This makes collaboration incredibly easy, whether your team is in the same office or spread across the globe. Forget about wrestling with complex data files or trying to decipher cryptic error messages. With an HTML report, everyone can access the same information and contribute to the analysis. You can easily attach the report to an email, upload it to a shared drive, or even host it on a web server for wider distribution. The portability and accessibility of HTML reports streamline the communication process and foster a more collaborative environment.
Visualizations: HTML reports can include charts, graphs, and other visualizations that make it easier to identify trends and patterns in your data. A picture is worth a thousand words, and this is especially true when it comes to load testing results. Instead of sifting through endless rows of numbers, you can quickly grasp the key performance indicators and identify potential bottlenecks. Visualizations can highlight areas of concern that might otherwise go unnoticed, allowing you to proactively address performance issues. The ability to see the data in a visual format empowers you to make data-driven decisions and optimize your system for maximum performance. From response time distributions to error rate trends, visualizations bring your load testing data to life.
Interactivity: Some HTML report generators offer interactive features, allowing you to zoom in on specific data points, filter results, and explore the data in more detail. This level of interactivity allows for a deeper dive into the test results, enabling you to uncover hidden insights and drill down into the root cause of performance problems. You can explore different scenarios, compare performance metrics, and identify areas for optimization. Interactive features transform the report from a static document into a dynamic tool for exploration and analysis. This hands-on approach empowers you to take ownership of the data and gain a more comprehensive understanding of your system's performance characteristics. With interactive reports, you're not just reading the results; you're actively engaging with them.

Setting up k6 and the HTML Reporter

Okay, let's get practical. First, you'll need k6 installed. If you haven't already, head over to the k6 website (https://k6.io/) and follow the installation instructions for your operating system. It's usually a pretty straightforward process. Once k6 is installed, you can verify it by running k6 version in your terminal. This will display the version of k6 that is installed on your system, confirming that the installation was successful.

Next, you'll need to install a k6 HTML reporter. There are a few options available, but a popular one is k6-reporter. You can install it using npm (Node Package Manager) if you have Node.js installed. If not, you'll need to install Node.js first. Once Node.js is installed, open your terminal and run the following command:

npm install -g k6-reporter

This command will install the k6-reporter globally, making it available for use in any k6 project. After the installation is complete, you can verify it by running k6-reporter --version in your terminal. This will display the version of k6-reporter that is installed on your system. With k6 and the HTML reporter installed, you're ready to start generating HTML reports from your k6 load tests. Remember to keep your Node.js and npm versions updated to ensure compatibility and access to the latest features and security patches.

Writing Your k6 Script

Now for the fun part! Let's create a simple k6 script. This script will make a request to a website and measure the response time. Create a file named script.js (or whatever you prefer) and add the following code:

import http from 'k6/http';
import { check, sleep } from 'k6';

export const options = {
  vus: 10, // Virtual Users
  duration: '10s', // Duration of the test
};

export default function () {
  const res = http.get('https://test.k6.io');
  check(res, {
    'status is 200': (r) => r.status === 200,
  });
  sleep(1);
}

Let's break down this script:

import http from 'k6/http';: This line imports the http module from k6, which allows us to make HTTP requests.
import { check, sleep } from 'k6';: This line imports the check and sleep functions from k6. The check function allows us to verify that the response status code is 200, and the sleep function pauses the execution of the script for 1 second.
export const options = { ... };: This defines the options for our test. We're setting the number of virtual users (vus) to 10 and the duration of the test to 10 seconds. These options control the intensity and duration of the load test, allowing you to simulate different user scenarios and measure the performance of your system under varying loads.
export default function () { ... };: This is the main function that k6 will execute. Inside this function, we make a GET request to https://test.k6.io and check if the response status code is 200. We then pause the execution for 1 second.

Feel free to modify the script to test your own website or API. You can adjust the number of virtual users, the duration of the test, and the target URL to simulate different load scenarios and measure the performance of your system under various conditions. Experiment with different request types (GET, POST, PUT, DELETE) and add more complex checks to verify the correctness of the responses. Remember to tailor the script to your specific testing needs and objectives. The key is to create a realistic simulation of user behavior to accurately assess the performance of your system under load.

Generating the HTML Report

Now, the moment we've all been waiting for! To generate the HTML report, run the following command in your terminal:

k6 run script.js --out html=report.html

This command tells k6 to run the script.js file and output the results to an HTML file named report.html. The --out html=report.html flag specifies the output format and the filename. After the test has finished running, you'll find the report.html file in the same directory as your script.js file. You can then open this file in your web browser to view the HTML report.

If you're using k6-reporter, you can pipe the output of k6 to the reporter. First, run the k6 test with the json output option:

k6 run script.js --out json=result.json

Then, use k6-reporter to generate the HTML report:

k6-reporter result.json -o report.html

This command reads the JSON output from result.json and generates an HTML report named report.html. The -o report.html flag specifies the output filename. This method provides more flexibility and customization options for generating HTML reports. You can use various flags with k6-reporter to customize the appearance and content of the report. For example, you can add a title, description, and custom CSS styling to the report.

Customizing the Report

The beauty of HTML reports lies in their customizability. You can often tweak the report's appearance and content to better suit your needs. For instance, with k6-reporter, you can use command-line flags to set the report title, add a custom logo, and even inject custom CSS. Customization allows you to tailor the report to your specific brand and reporting requirements. You can add your company logo, change the color scheme, and adjust the layout to match your corporate style guide. By customizing the report, you can create a more professional and visually appealing document that effectively communicates the results of your load tests. Furthermore, you can add custom sections to the report to include additional information, such as test objectives, methodology, and conclusions.

For more advanced customization, you might need to explore other HTML reporter options or even create your own custom reporter using k6's JavaScript API. This gives you complete control over the report's structure and content, allowing you to create highly specialized reports that meet your unique needs. Creating a custom reporter requires a deeper understanding of k6's internal workings and JavaScript programming. However, the effort can be well worth it if you need to generate highly customized reports that are not available through existing reporter tools. With a custom reporter, you can integrate your load testing results with other monitoring tools, generate reports in different languages, and create interactive dashboards that provide real-time insights into your system's performance.

Analyzing the HTML Report

Okay, you've generated your HTML report. Now what? It's time to analyze the results! The HTML report typically includes a summary of the test, key performance indicators (KPIs), and visualizations of the data. The summary provides an overview of the test, including the number of virtual users, the duration of the test, and the overall pass/fail status. The KPIs highlight the most important performance metrics, such as response time, error rate, and requests per second. The visualizations, such as charts and graphs, provide a visual representation of the data, making it easier to identify trends and patterns.

Here are some key areas to focus on:

Response Time: Pay close attention to the average, minimum, and maximum response times. Look for any spikes or anomalies that might indicate performance bottlenecks. A sudden increase in response time could indicate that your system is struggling to handle the load. Investigate the root cause of these spikes and identify areas for optimization. Also, analyze the response time distribution to understand how response times are distributed across different requests.
Error Rate: A high error rate indicates that something is wrong with your system. Investigate the errors to determine the cause and take corrective action. High error rates can be caused by various factors, such as server overload, network issues, or application bugs. Analyze the error logs to identify the specific errors that are occurring and the frequency of each error.
Requests per Second (RPS): This metric indicates how many requests your system can handle per second. Track the RPS to see how your system scales under load. A decreasing RPS could indicate that your system is reaching its capacity. Monitor the RPS closely to identify performance bottlenecks and optimize your system for maximum throughput.
Virtual Users (VUs): Monitor the number of virtual users to ensure that the test is simulating the expected load. An insufficient number of virtual users could result in inaccurate performance measurements. Adjust the number of virtual users to accurately simulate the expected load on your system.

By carefully analyzing these metrics, you can identify performance bottlenecks and areas for optimization, allowing you to improve the performance and scalability of your system. Remember to compare the results of different tests to track progress and identify regressions. Regular load testing and analysis are crucial for maintaining the performance and stability of your system.

Conclusion

Generating HTML reports with Grafana k6 is a fantastic way to make your load testing results more accessible, shareable, and understandable. By following the steps outlined in this guide, you can easily generate HTML reports from your k6 load tests and gain valuable insights into the performance of your system. Remember to customize the reports to meet your specific needs and to analyze the results carefully to identify areas for optimization.

So there you have it! Go forth and create some awesome HTML reports. Happy testing!