Skip to main content

HTTP Methods

The HTTP protocol specifies several possible methods or verbs. Each HTTP method represents a different type of request intent:

info

GET: the client wants to retrieve information

POST: the client wants to create or update data on the server

PUT: the client wants to update or replace data on the server

DELETE: the client wants to delete some data on the server

Each HTTP method has different variations in how the request is formatted, and when/why it should be used by a client. In addition, some types of requests can be treated as "idempotent" (can be done many times without causing additional changes).

  1. GET Requests

GET requests are used to retrieve information from the server, based on a specific URL. GET requests do not contain a request body. However, clients may include additional data as query parameters options attached to the main URL. Query params start with a ?, and are formatted as key=value pairs separated by ampersands: /endpoint?a=1&b=stuff. Spaces and special characters in URLs may need to be URL-encoded, where the original value is replaced by a % and a number: ?a=Some Value might become ?a=Some%20Value.

Since GET requests are only used for retrieving data, servers should not update data in response to a GET. This means it should be safe to make the same GET request multiple times without causing side effects.

  1. POST Requests

POST requests are used to tell the server to update some data or process some information. POSTs typically include all relevant information in the body of the request, and rarely include query params.

POST request bodies typically use a few common formats

"Form-encoded": the same key=value structure as query parameters, but in the body of a POST "Multi-part form data": a delimited format that splits the body into sections "JSON": a string representation of JavaScript data structures like objects and arrays

  1. PUT Requests

PUT requests are very similar to POST requests. Both involve sending data to the server with an intent to update. The intended difference is that a PUT is intended to create or replace a value, while a POST is intended to create or update a value. Conceptually, a PUT should be safe to do multiple times in a row, while a POST is likely to cause something to happen separately for each request.

  1. PATCH Requests

PATCH requests are also similar to PUT requests, but the intent is to send a partial representation of an item, while PUT is meant to send the complete representation of an item.

  1. DELETE Requests

DELETE requests are used to ask a server to delete some data. Conceptually, it should be safe to make a DELETE request multiple times - if a value is already gone, the server ought to ignore the request.