Load testing basics (Postman)

Introduction

Load testing helps check if a website or app can handle many users at once without slowing down or crashing.

Before launching a new website to make sure it can handle visitors.

When adding new features that might affect performance.

To find the maximum number of users your app can support.

After fixing bugs to confirm the app still works well under stress.

To compare performance before and after updates.

Syntax

Postman

1. Open Postman.
2. Create or select a request.
3. Click on the "Runner" button.
4. Set the number of iterations (how many times to run).
5. Use "Delay" to add wait time between requests.
6. Click "Run" to start the load test.

Postman Runner simulates multiple requests but is limited for heavy load testing.

For more advanced load testing, use Postman with external tools like Newman and a load generator.

Examples

This runs the request 50 times with 100 milliseconds pause between each.

Postman

Runner settings:
Iterations: 50
Delay: 100 ms
Run the test

This runs 100 requests as fast as possible to simulate high load.

Postman

Runner settings:
Iterations: 100
Delay: 0 ms
Run the test

Sample Program

This example tests if the sample API can handle 10 quick requests in a row.

Postman

GET https://jsonplaceholder.typicode.com/posts/1

// Steps to run load test in Postman Runner:
// 1. Open this GET request in Postman.
// 2. Click Runner.
// 3. Set Iterations to 10.
// 4. Set Delay to 50 ms.
// 5. Click Run.

// Expected result:
// All 10 requests complete successfully with status 200.
// Response times are shown in Runner summary.

Important Notes

Postman load testing is good for small to medium tests but not for very high traffic.

Always monitor server health during load tests to avoid crashes.

Use environment variables in Postman to test different data during load tests.

Summary

Load testing checks how many users your app can handle at once.

Postman Runner can simulate multiple requests to do basic load testing.

For heavy load tests, combine Postman with other tools like Newman or dedicated load testers.