K6 performance test

 Here is a Beginner k6 Learning Syllabus + API Performance Examples designed specifically for you (Automation QA → Selenium → Playwright → API Testing → Performance Testing) 🚀

---

🚀 Beginner k6 Learning Syllabus

Module 1 — Performance Testing Basics

Before learning k6, understand:

What is Performance Testing?

• Load Testing

• Stress Testing

• Spike Testing

• Endurance Testing

Important Terms

Term	Meaning
VU	Virtual Users
TPS	Transactions per second
Response Time	API response duration
Throughput	Requests per second
Latency	Time before request starts

---

Module 2 — Installing k6

Ways to Install:

• Chocolatey (You tried already)

• Winget

• Download Binary

Verify:

k6 version

---

Module 3 — First k6 Script

Create file:

test.js

Code:

import http from 'k6/http';

export default function () {
  http.get('https://test.k6.io');
}

Run:

k6 run test.js

---

Module 4 — Virtual Users (Load Testing)

Example:

import http from 'k6/http';

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

export default function () {
  http.get('https://test.k6.io');
}

This means:

• 10 users

• 10 seconds

---

Module 5 — k6 Options

Common Options:

export const options = {
  vus: 20,
  duration: '30s',
  iterations: 100,
};

Options Explanation:

Option	Meaning
vus	Virtual users
duration	Test time
iterations	Number of calls

---

🚀 API Performance Examples

Now real-world API examples 👇

---

Example 1 — Simple API Load Test

import http from 'k6/http';

export const options = {
  vus: 5,
  duration: '10s',
};

export default function () {
  http.get('https://reqres.in/api/users?page=2');
}

Run:

k6 run api_test.js

---

Example 2 — API with Validation

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

export const options = {
  vus: 5,
  duration: '10s',
};

export default function () {

  const res = http.get('https://reqres.in/api/users');

  check(res, {
    'status is 200': (r) => r.status === 200,
  });

}

---

Example 3 — POST API Performance

import http from 'k6/http';

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

export default function () {

  const payload = JSON.stringify({
    name: "Sunil",
    job: "QA Engineer"
  });

  const params = {
    headers: {
      'Content-Type': 'application/json',
    },
  };

  http.post('https://reqres.in/api/users', payload, params);

}

---

Example 4 — API with Multiple Requests

import http from 'k6/http';

export const options = {
  vus: 10,
  duration: '20s',
};

export default function () {

  http.get('https://reqres.in/api/users');

  http.get('https://reqres.in/api/users/2');

}

---

Example 5 — Ramp Up Users (Realistic Test)

export const options = {
  stages: [
    { duration: '10s', target: 5 },
    { duration: '20s', target: 10 },
    { duration: '10s', target: 0 },
  ],
};

This means:

• 0 → 5 users

• 5 → 10 users

• 10 → 0 users

Realistic Load Testing 🚀

---

Example 6 — Response Time Validation

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

export default function () {

  const res = http.get('https://reqres.in/api/users');

  check(res, {
    'response time < 500ms': (r) => r.timings.duration < 500,
  });

}

---

Example 7 — Authentication API

import http from 'k6/http';

export default function () {

  const payload = JSON.stringify({
    email: "eve.holt@reqres.in",
    password: "cityslicka"
  });

  const params = {
    headers: {
      'Content-Type': 'application/json',
    },
  };

  http.post('https://reqres.in/api/login', payload, params);

}

---

Real-World Example (Your QA Project)

Example: Login → Get Dashboard → Logout

import http from 'k6/http';

export default function () {

  http.post('https://api.site.com/login');

  http.get('https://api.site.com/dashboard');

  http.post('https://api.site.com/logout');

}

---

Reporting (Important)

k6 shows report automatically:

Example Output:

checks................: 100%
http_req_duration.....: avg=250ms
http_reqs.............: 500
vus...................: 10

---

Tools Similar to k6

Tool	Usage
Apache JMeter	Traditional performance tool
Grafana	Dashboard
Prometheus	Metrics
Locust	Python performance

---

Learning Path (Recommended for You)

Day 1

• Install k6

• Run simple test

Day 2

• VUs

• Duration

• Iterations

Day 3

• API Testing

• POST Request

Day 4

• Validation

• Response time

Day 5

• Real project test

---

Why k6 is Good for You

You already know:

• Selenium

• Playwright

• Rest Assured

• Java

k6 adds:

✅ Performance Testing
✅ API Load Testing
✅ DevOps Friendly
✅ Cloud Execution

Very high demand skill 🔥

---

Next I can give:

• Real interview questions

• Advanced k6 framework

• CI/CD Integration

Just tell me 👍