Load Testing with k6: A Step-by-Step Guide for Performance Engineers

Quick Answer: k6 is a JavaScript-based load testing tool that runs performance tests from the command line. To start: install k6, write a test script with virtual users and duration, run from CLI, and analyze response time metrics (p50, p95, p99) and error rates.

What is k6?

k6 is an open-source load testing tool built in Go with JavaScript scripting. It measures response times, throughput, error rates, and custom metrics.

Install k6

# macOS
brew install k6

# Windows
choco install k6

# Linux
sudo apt-get install k6

Write Your First k6 Test

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

export const options = {
  vus: 10,
  duration: '30s',
};

export default function () {
  const res = http.get('https://api.example.com/users');
  check(res, {
    'status is 200': (r) => r.status === 200,
    'response time < 500ms': (r) => r.timings.duration < 500,
  });
  sleep(1);
}

Run the Test

k6 run load-test.js
k6 run --vus 50 --duration 60s load-test.js

Understanding k6 Metrics

Integrate k6 with CI/CD

# GitHub Actions
- uses: grafana/[email protected]
  with:
    filename: load-test.js

When to Use k6 vs JMeter

k6 is better for developer-centric teams and CI/CD. JMeter is better for protocol diversity and enterprise environments.

Training Resources

Master performance testing with SkilBrill Load Testing Training.

FAQ

Is k6 better than JMeter?

k6 is better for modern CI/CD workflows. JMeter is better for protocol diversity and enterprise environments.

Written by SkilBrill Training Institute

September 18, 2026 · 2 min read