What is the Difference Between POST and PUT in HTTP?

Introduction

HTTP is a protocol used to transfer data between a web server and a web browser. It is the foundation of the World Wide Web. HTTP defines a set of methods that can be used to request data from a server. Two of the most commonly used methods are POST and PUT. In this article, we will discuss the differences between POST and PUT in HTTP.

POST vs PUT

The POST method is used to send data to a server. It is typically used when submitting a form or uploading a file. The data is sent in the body of the request and is not visible in the URL. The POST method is not idempotent, meaning that multiple requests with the same data may have different effects. For example, submitting a form multiple times may result in multiple records being created in a database.

The PUT method is used to update existing data on a server. It is typically used when updating a record in a database. The data is sent in the body of the request and is not visible in the URL. The PUT method is idempotent, meaning that multiple requests with the same data will have the same effect. For example, sending a PUT request multiple times with the same data will result in the same record being updated in the database.

Example

Let’s look at an example of how POST and PUT are used in HTTP. We will use the cURL command line tool to make the requests.

To make a POST request, we can use the following command:

curl -X POST -d 'name=John&age=30' http://example.com/users

This command will send a POST request to the URL http://example.com/users with the data name=John&age=30 in the body of the request. This data could be used to create a new user in a database.

To make a PUT request, we can use the following command:

curl -X PUT -d 'name=John&age=31' http://example.com/users/1

This command will send a PUT request to the URL http://example.com/users/1 with the data name=John&age=31 in the body of the request. This data could be used to update an existing user in a database.

Conclusion

In this article, we discussed the differences between POST and PUT in HTTP. The POST method is used to send data to a server, while the PUT method is used to update existing data on a server. We also looked at an example of how to make POST and PUT requests using the cURL command line tool.