# Postman vs curl: A Complete Beginner’s Guide to API Testing and Automation

## Introduction

You've just built a backend API, or maybe you're consuming someone else’s. Either way, testing it manually via browser is a pain. You want quick, reliable, repeatable testing. That’s where tools like Postman and curl come in.

But which one should you use? How do you even get started? This post is your go-to beginner guide—whether you're debugging your first API or automating your tenth.

---

## Part 1: Postman – GUI for API Testing

### What is Postman?

Postman is a user-friendly desktop application for testing APIs. It supports all HTTP methods like GET, POST, PUT, DELETE and provides built-in support for test scripting, environments, mock servers, and API documentation.

---

### How to Install Postman

* Visit [https://www.postman.com/downloads](https://www.postman.com/downloads)
    
* Download for Windows, Mac, or Linux
    
* Install and open the app
    

**OR**

* Open Visual Studio Code
    
* Go to Extensions (Ctrl + Shift + X)
    
* Search for "Postman" and install the official extension
    

---

### Getting Started: Your First Requests

#### GET Request

Method: GET  
URL: `https://jsonplaceholder.typicode.com/posts/1`

Click Send and view the response.

#### POST Request

1. Set method to POST
    
2. URL: `https://jsonplaceholder.typicode.com/posts`
    
3. Go to Body → raw → JSON
    
4. Paste:
    

```bash
{
  "title": "Deepak",
  "body": "Learning Postman",
  "userId": 1
}
```

Click Send.

---

### Write Test Scripts in Postman

Go to the Tests tab and paste:

```bash
pm.test("Status code is 201", function () {
  pm.response.to.have.status(201);
});
```

---

### Convert to curl

* Click the `</>` Code button
    
* Choose curl
    
* Copy and paste it in terminal
    

---

## Part 2: curl – Command-line for Pros

### What is curl?

**curl stands for "Client URL".** It is a lightweight command-line tool to send HTTP requests. It’s fast, scriptable, and perfect for automation in CI/CD pipelines.

---

### How to Install curl

#### Windows:

* Good news: If you're using Windows 10 (v1803 and above) or Windows 11, **curl is pre-installed**.
    
* To verify, open Command Prompt or PowerShell and run:
    

```bash
curl --version
```

If you see version details, you're ready to use curl.

#### For older versions or latest curl:

* Download from https://curl.se/windows
    
* Extract and add to your PATH if needed
    

---

### Basic curl Commands

#### GET Request

```bash
curl https://jsonplaceholder.typicode.com/posts/1
```

#### POST Request

```bash
curl -X POST https://jsonplaceholder.typicode.com/posts \
  -H "Content-Type: application/json" \
  -d '{"title":"Deepak","body":"Learning curl","userId":1}'
```

#### Add Authorization

```bash
curl -H "Authorization: Bearer YOUR_TOKEN" https://api.example.com/data
```

#### Save Response to File

```bash
curl https://api.example.com/data -o response.json
```

---

## Switching Between Postman and curl

| Task | Tool | How to do it |
| --- | --- | --- |
| Convert Postman to curl | Postman | Click Code (&lt;/&gt;) → Select curl |
| Convert curl to Postman | Postman | Import → Raw Text → Paste curl cmd |

---

## Postman vs curl – Feature Comparison

| Feature | Postman | curl |
| --- | --- | --- |
| Interface | GUI | Command-line (CLI) |
| Ease of Use | Beginner-friendly | Requires command knowledge |
| Scripting | Built-in test scripts | External scripting only |
| Speed | Slower (GUI overhead) | Fast & lightweight |
| Automation | Limited | Great in CI/CD & Bash |
| Collaboration | Team sharing & docs | Not built-in |

---

## When to Use What?

Use Postman if you’re exploring or debugging an API visually, or working in a team.

Use curl if you need fast, scriptable HTTP calls, or you're automating workflows.

---

## Alternatives to Postman and curl

| Tool | Type | Description |
| --- | --- | --- |
| Insomnia | GUI | Similar to Postman, with strong GraphQL support |
| HTTPie | CLI | Like curl but with human-readable syntax |
| Paw | GUI (Mac) | Postman alternative for Mac with advanced features |
| Hoppscotch | Web | Lightweight Postman alternative that runs in your browser |

---

## Final Thoughts

Both Postman and curl are indispensable tools for API developers. Postman is your go-to for designing, debugging, and collaborating; curl is your trusted tool for scripting, quick tests, and CI/CD pipelines.

Master both to cover all your API testing needs—from visual tools to terminal automation.