In the previous chapter, you used curl to make API calls from the terminal. It works. But imagine testing 50 endpoints every sprint. Typing curl commands, remembering flags, copy-pasting JSON bodies. You'd lose your mind by Wednesday.
That's why Postman exists. Postman is a GUI tool for API testing. You pick the method from a dropdown, paste the URL, click Send. Response shows up instantly — formatted, color-coded, searchable. No terminal gymnastics.
Key Point: Postman is the #1 API testing tool in the industry. Over 30 million developers and testers use it. If a job posting says "API testing experience" — they mean Postman.
Fair question. You CAN test APIs with curl, Python scripts, or even browser DevTools. But here's the thing — Postman does everything they do, plus a LOT more.
Let's see the same POST request done in curl, Python, and Postman. You'll understand why Postman wins for daily testing.
# curl — you type all of this every time
curl -s -X POST https://jsonplaceholder.typicode.com/posts \
-H "Content-Type: application/json" \
-H "Authorization: Bearer eyJhbGciOiJIUzI1NiJ9..." \
-d '{
"title": "My Post",
"body": "Hello from curl",
"userId": 1
}' | python3 -m json.tool# Python — cleaner but needs setup
import requests
response = requests.post(
"https://jsonplaceholder.typicode.com/posts",
headers={
"Content-Type": "application/json",
"Authorization": "Bearer eyJhbGciOiJIUzI1NiJ9..."
},
json={
"title": "My Post",
"body": "Hello from Python",
"userId": 1
}
)
print(response.status_code)
print(response.json())# Postman — you just fill in the blanks:
Method: POST (dropdown)
URL: https://jsonplaceholder.typicode.com/posts
Headers: Content-Type: application/json (auto-set)
Authorization: Bearer eyJhbGci...
Body: { "title": "My Post", "body": "Hello", "userId": 1 }
Click Send. Done.All three do the same thing. But in Postman, you set it up ONCE and it stays saved. Tomorrow, you click it again. No retyping. No copy-pasting. That's the difference between a tool and a platform.
| Tool | Best For | Example |
|---|---|---|
| Postman | Daily API testing, exploration, team collaboration | Testing 50 endpoints every sprint |
| curl | Quick one-off checks, server debugging, CI scripts | SSH into production server, check if API is alive |
| Python/Java code | Automated regression suites, CI/CD pipelines | Running 500 API tests on every PR merge |
| Browser DevTools | Inspecting existing API calls from a web app | Debugging why the login page is slow |
In most QA teams, the workflow is: explore APIs in Postman first, figure out test cases, then automate them in code (Python/Java/RestAssured) later. Postman is phase 1. Automation is phase 2. You need both.
Q: What is Postman and why do you use it?
A: Postman is an API development and testing platform. I use it for sending HTTP requests, inspecting responses, organizing tests into collections, writing test scripts, and sharing API specs with my team. It supports environment variables so I can switch between dev, staging, and production with one click. For manual exploratory testing of APIs, nothing beats Postman.
Q: Can you test APIs without Postman?
A: Yes. You can use curl from the command line, write scripts in Python or Java, or use browser DevTools to inspect live API calls. But Postman saves time because it stores requests, supports variables, lets you write test assertions, and makes collaboration easy. For quick checks on a remote server, I use curl. For daily testing, Postman. For CI/CD automation, I use RestAssured or Python requests.
Key Point: Postman is the #1 API testing tool. Use it for exploration and manual testing. Use code for automation. Know when to use each.