HTTP POST is a request method used in the Hypertext Transfer Protocol (HTTP) to send data from a client (such as a web browser or application) to a server. The primary purpose of POST is to submit data to a specified resource, which usually results in a change on the server, such as creating or updating a resource.
Key characteristics of HTTP POST:
- Data Transmission: Data is sent in the body of the HTTP request, not in the URL. This allows for sending large amounts of data and makes POST suitable for sensitive information, as the data is not exposed in the browser’s address bar or history.
- Common Uses: POST is widely used for submitting web forms, uploading files, sending JSON or XML data to APIs, and other operations that require the server to process or store the submitted data.
- Not Idempotent: Unlike some other HTTP methods (such as PUT), POST is not idempotent. Sending the same POST request multiple times can result in multiple resources being created or multiple actions being performed.
- No Caching or Bookmarking: POST requests are not cached by browsers and cannot be bookmarked, which is different from GET requests.
- Content-Type Header: The format of the data in the request body is specified by the
Content-Typeheader (e.g.,application/json,multipart/form-data,application/x-www-form-urlencoded).
Example Use Case:
When a user fills out a registration form on a website and clicks “Submit,” the browser sends a POST request to the server with the form data in the request body. The server processes this data, creates a new user account, and returns a response.