Skip to content
Postman API Testing Tips

How To Send Post Using Postman

API Testing Blog

Understanding POST Requests

POST requests are used to send data to a server to create or update a resource. This is in contrast to GET requests, which are used to retrieve data from a server. When sending data with a POST request, the data is typically encoded in the body of the request, using one of several common formats such as JSON, XML, or form data.

Sending POST Requests with Postman: A Step-by-Step Guide

  1. Open Postman and Create a New Request: Start by opening the Postman app and clicking on the “New” button to create a new request.
  2. Select the POST Method: In the request window, select the “POST” method from the dropdown menu. Make sure the “POST” method is chosen, as this dictates how the data is sent to the API endpoint.
  3. Input the API Endpoint: In the “Enter request URL” field, paste the specific API endpoint you want to send the data to. For example, if you’re sending data to a user registration endpoint, it might look like this: https://api.example.com/users.
  4. Add Request Headers: In the “Headers” tab, you can add any necessary headers. Common headers include:
    • Content-Type: This specifies the format of the data you are sending in the request body. For JSON data, use application/json.
    • Authorization: This header might be used to authenticate your request, especially if the API requires authentication.

Example:

Content-Type: application/json
Authorization: Bearer your_api_token
  1. Construct the Request Body: This is the heart of the POST request. In the “Body” tab, select the format of the data you want to send, such as JSON, form-data, or XML. The specific format depends on the API’s requirements. Let’s illustrate with a JSON example:

Example:

{
  "name": "John Doe",
  "email": "johndoe@example.com",
  "password": "your_password"
}
  1. Send the Request: Once you’ve configured everything, click on the “Send” button to send the request to the server. Postman will then display the response from the server.
  2. Interpret the Response: The server will respond with a status code indicating the success or failure of the POST request. For successful requests, you will typically see a 200 (OK) status code, while an error might be indicated by codes like 400 (Bad Request), 401 (Unauthorized), or 500 (Internal Server Error). The response body might also contain valuable information, such as newly created resources or error messages.

Practical Example: Sending User Data to an API Endpoint

Let’s say we need to send user registration data to an API endpoint that accepts data in JSON format. Here’s a breakdown of how to do it in Postman:

  1. Open Postman and Create a New Request: Start with a new request in Postman.
  2. Select POST Method: Ensure the “POST” method is selected.
  3. Input API Endpoint: Enter the API endpoint URL for user registration. For example: https://api.example.com/users.
  4. Add Headers: Add the “Content-Type” header to indicate the JSON format:
Content-Type: application/json
  1. Construct the Request Body: Create a JSON object containing the user data:
{
  "name": "Alice Smith",
  "email": "alice@example.com",
  "password": "securepassword"
}
  1. Send the Request: Click the “Send” button.
  2. Interpret the Response: Analyze the response for the status code and any additional information provided in the response body. If successful, you will likely receive a 200 (OK) status code and maybe even an ID for the newly created user.

Sending POST Requests with Parameters

You can also include parameters in your POST request. This is often useful to pass additional information with the request body:

  1. Select the “Params” Tab: Click on the “Params” tab in Postman.
  2. Add Key-Value Pairs: Add pairs with the parameter name as the key and parameter value as the value. You can add multiple parameters.

Example:

Key     | Value
--------|--------
source  | web
referer | google.com
  1. Send the Request: Click the “Send” button. The parameters will be included in the request when it’s sent.

Debugging POST Requests with Postman

Sometimes, POST requests might not work as expected. In these scenarios, Postman offers helpful tools for debugging:

  1. Response Body: Inspect the response body to get insights into the reason for failure, including error messages.
  2. Request Headers: Check the request headers to ensure you are sending the correct content type and authorization headers.
  3. Request Body: Verify the request body is formatted correctly and matches the API documentation.
  4. Console Log: Postman’s console can provide further information about the request and response process.
  5. Network Tab (Chrome DevTools): For more advanced debugging, consider using the Network tab in Chrome DevTools to observe network requests and responses.

Sending POST Requests with Different Data Formats

POST requests can be used with different data formats besides JSON, such as:

  • XML: Used for structured data, often in web services.
  • Form data: For sending data that might be a form submission on a web page.

Postman allows you to easily switch between different formats by selecting them in the “Body” tab.

Using Postman Collections and Environments

For more complex workflows involving multiple API requests, Postman provides features like Collections and Environments:

  • Collections: Organize multiple related requests into a collection, making it easier to manage and execute them together.
  • Environments: Store variables that can be used in multiple requests, such as API keys, base URLs, or authentication tokens, allowing for easy switching between development and production environments.

Conclusion

Postman is a powerful tool for sending POST requests for API testing. By learning the basics of constructing POST requests and utilizing Postman’s features, you can streamline your API testing workflow and efficiently interact with APIs. Remember to always refer to the API documentation for specific requirements and data formats that your API endpoint expects.

API Testing Blog