Postman POST PUT DELETE Requests

GET requests only read data. POST, PUT, PATCH, and DELETE requests make changes — they create, update, or remove data on a server. This topic covers all four with clear examples and diagrams.

The CRUD Model

Every API is built around four actions called CRUD. Each HTTP method maps to one of these actions:

POST – Create New Data

A POST request sends new data to the server to be saved. Think of filling in a registration form and clicking Submit — that button triggers a POST request.

You (Postman)                The Server
     │                            │
     │── POST /posts ──────────▶ │
     │   Body: { title, body }    │  (Server saves the new post)
     │◀── 201 Created ────────── │
     │                            │

Send a POST Request

1. Open a new request tab in Postman
2. Change the method dropdown to POST
3. Enter this URL: https://jsonplaceholder.typicode.com/posts
4. Click the Body tab below the URL bar
5. Select the raw radio button
6. Choose JSON from the format dropdown that appears on the right
7. Paste this into the text area:

   {
     "title": "My First Post",
     "body": "This is the content of my post.",
     "userId": 1
   }

8. Click Send

The server responds with 201 Created and returns the new post with an ID assigned to it. This is not a real save on the test server, but it shows you exactly how a real POST works.

PUT – Replace an Entire Record

A PUT request replaces all the data in an existing record. If you send only some fields, the missing fields get wiped. Use PUT when you want to overwrite the whole record.

You (Postman)                        The Server
     │                                   │
     │── PUT /posts/1 ────────────────▶  │
     │   Body: { title, body, userId }   │  (Server replaces post 1)
     │◀── 200 OK ──────────────────────  │
     │                                   │

Send a PUT Request

1. Change the method to PUT
2. Use this URL: https://jsonplaceholder.typicode.com/posts/1
3. In the Body tab, use raw JSON:

   {
     "id": 1,
     "title": "Updated Title",
     "body": "Updated content.",
     "userId": 1
   }

4. Click Send

A 200 OK response confirms the server accepted the update.

PATCH – Update Part of a Record

A PATCH request changes only the fields you send. All other fields stay the same. Use PATCH when you want to change a single detail, like updating just the title of a blog post.

Send a PATCH Request

1. Change the method to PATCH
2. Use this URL: https://jsonplaceholder.typicode.com/posts/1
3. In the Body tab, use raw JSON with only the field you want to change:

   {
     "title": "Only the Title Changed"
   }

4. Click Send

The server returns the updated post. Only the title changed. The body and userId remain untouched.

PUT vs PATCH – Key Difference

DELETE – Remove a Record

A DELETE request tells the server to remove a resource. You usually do not send a body with DELETE — the URL itself identifies what to remove.

You (Postman)               The Server
     │                          │
     │── DELETE /posts/1 ─────▶ │
     │                          │  (Server removes post 1)
     │◀── 200 OK ───────────── │
     │                          │

Send a DELETE Request

1. Change the method to DELETE
2. Use this URL: https://jsonplaceholder.typicode.com/posts/1
3. Do not add anything in the Body tab
4. Click Send

The test server returns 200 OK with an empty body {}, confirming the deletion.

Summary of Status Codes for Each Method

Summary

POST creates new data. PUT replaces an entire record. PATCH updates only the fields you specify. DELETE removes a record. The URL targets the resource and the HTTP method tells the server what action to take on it.