GET vs POST: Understanding HTTP Request Methods

Quick answer: GET vs POST

GET retrieves data without changing anything on the server, while POST sends data to create or modify resources.

Try Postman today →

Retrieving and Sending Data with GET and POST

In short:

• Use GET when you want to retrieve data without changing anything on the server.
• Use POST when you need to send data to create or modify resources.

What GET Does

The HTTP GET method requests data from a server at a specific URI. It’s designed to retrieve information without modifying server state, making it safe to call repeatedly without side effects.

Example: Retrieving user data with GET

GET /api/users/12345 HTTP/1.1
Host: api.example.com

The request body contains the data for the user:

HTTP/1.1 200 OK
Content-Type: application/json

{
  "id": "12345",
  "name": "Penny Ostman",
  "email": "[email protected]",
  "role": "Developer"
}

GET requests can include query parameters in the URL to filter or customize results:

GET /api/users?role=developer&limit=10 HTTP/1.1

Since GET requests don’t modify data, browsers and proxies can safely cache responses to improve performance.

When to Use GET

• Fetching a list of resources (GET /products)
• Retrieving a specific resource (GET /users/123)
• Searching or filtering data (GET /articles?category=tech)
• Reading data without side effects
• Operations that should be bookmarkable or shareable via URL

What POST Does

The HTTP POST method submits data to a server to create a new resource or trigger an action. Unlike GET requests, POST requests include a request body with the sent data and the ability to change the server state.

Example: Creating a new user with POST

POST /api/users HTTP/1.1
Content-Type: application/json

{
  "name": "Penny Ostman",
  "email": "[email protected]"
}

The server responds with details about the newly created resource:

HTTP/1.1 201 Created
Location: /api/users/12345
Content-Type: application/json

{
  "id": "12345",
  "name": "Penny Ostman",
  "email": "[email protected]"
}

The Location header in the response tells the client where the new resource lives. The POST method is not idempotent, so sending the same POST request twice may create duplicate entries.

When to Use POST

• Creating new resources (POST /orders)
• Submitting forms or file uploads
• Triggering actions (POST /payments)
• Sending large amounts of data
• Any operation that changes server state

Real-world examples of GET vs POST

GET is used for reading data from specific resources or collections, like /users/123 and /products. If you’re just viewing information without making changes, use GET.

POST is used when you need to send data to the server, whether creating new resources in collections like /users and /orders, or triggering actions like /checkout and /login.

Here are some common ways that GET and POST are used:

E-commerce

• GET /products → Browse product catalog

• GET /products/789 → View specific product details

• POST /orders → Create a new order

• POST /cart/items → Add item to shopping cart

User management

• GET /users → List all users

• GET /users/123 → Get a user’s profile

• POST /users → Register a new user

• POST /login → Authenticate a user

Content management

• GET /articles?category=tech → Browse articles by category

• GET /articles/456 → Read a specific article

• POST /articles → Create a new article

• POST /comments → Submit a comment

Search and filtering

• GET /search?q=postman → Search for content

• GET /users?role=admin&status=active → Filter users

• POST /reports/generate → Generate a custom report

How to Choose Between GET and POST

GET retrieves data without side effects, while POST submits data and can modify server state.

Key differences between GET and POST

Where the data lives

GET requests append data to the URL as query parameters (?name=value&role=admin), while POST requests send data in the request body. This fundamental difference affects everything from security to performance.

Because GET data lives in the URL, it appears in browser history, bookmarks, and server logs. This makes GET URLs shareable and bookmarkable, but dangerous for sensitive information. POST data stays hidden in the request body, so you can’t bookmark it, but you also won’t accidentally leak credentials.

Size and data types

URL length limits restrict GET requests to roughly 2,000-8,000 characters, depending on the browser. POST has no such restriction and can handle megabytes of data. GET can only transmit URL-safe text, while POST can send any data type specified by the Content-Type header, such as JSON, XML, or binary files.

Security Considerations

Never include sensitive data in a GET request.

❌ Bad practice:

GET /login?username=admin&password=secret123

This exposes credentials in browser history, server logs, proxy logs, and referrer headers.

POST /login HTTP/1.1
Content-Type: application/json

{
  "username": "admin",
  "password": "secret123"
}

Combined with HTTPS, POST keeps credentials encrypted and out of logs.

Caching behavior

GET requests are designed to be cached by browsers and CDNs, improving performance for frequently accessed data. POST requests typically aren’t cached because they usually trigger actions or modify resources.

Testing method behavior in Postman

You can see these differences with a simple collection.

1. Create a new collection called GET vs POST Demo.

2. Add two requests:

   • GET /users/:id (retrieve)

   • POST /users (create)

3. Set up a mock server to simulate responses:

   • Configure GET /users/:id to return 200 OK with user data

   • Configure POST /users to return 201 Created with a Location header

4. Click Send and observe the differences:

   • GET retrieves existing data

   • POST creates new resources

Optional: Add test scripts to verify correct status codes, response structure, and headers like Location or Content-Type.

Best practices for API design

• Use GET for safe, read-only operations that don’t modify data.

• Use POST when creating resources or performing actions with side effects.

• Never send sensitive data, such as passwords or tokens, in GET query parameters.

• Keep GET URLs bookmarkable and shareable when possible.

• Make GET requests idempotent and cacheable.

• Include proper status codes: 200 OK for GET, 201 Created for POST.

• Use query parameters in GET for filtering, sorting, and pagination.

• Document both methods with clear examples in Postman.

Quick Reference