POST

POST

The POST sends data to the server. The type of the body of the request is indicated by the Content-Type header.

The difference between PUT and POST is that PUT is idempotent: calling it once or several times successively has the same effect (that is no side effect), where successive identical POST may have additional effects, like passing an order several times.

A POST request is typically sent via an HTML form and results in a change on the server. In this case, the content type is selected by putting the adequate string in the enctype attribute of the <form> element or the formenctype attribute of the <input> or <button> elements:

• application/x-www-form-urlencoded: the keys and values are encoded in key-value tuples separated by '&', with a '=' between the key and the value. Non-alphanumeric characters in both keys and values are percent encoded: this is the reason why this type is not suitable to use with binary data (use multipart/form-data instead)
• multipart/form-data: each value is sent as a block of data ("body part"), with a user agent-defined delimiter ("boundary") separating each part. The keys are given in the Content-Disposition header of each part.
• text/plain

When the POST request is sent via a method other than an HTML form — like via an XMLHttpRequest — the body can take any type. As described in the HTTP 1.1 specification, POST is designed to allow a uniform method to cover the following functions:

• Annotation of existing resources
• Posting a message to a bulletin board, newsgroup, mailing list, or similar group of articles;
• Adding a new user through a signup modal;
• Providing a block of data, such as the result of submitting a form, to a data-handling process;
• Extending a database through an append operation.

Syntax

POST /test

Example

A simple form using the default application/x-www-form-urlencoded content type:

POST /test HTTP/1.1
Host: foo.example
Content-Type: application/x-www-form-urlencoded
Content-Length: 27

field1=value1&field2=value2

A form using the multipart/form-data content type:

POST /test HTTP/1.1
Host: foo.example
Content-Type: multipart/form-data;boundary="boundary"

--boundary
Content-Disposition: form-data; name="field1"

value1
--boundary
Content-Disposition: form-data; name="field2"; filename="example.txt"

value2
--boundary--

Specifications

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
POST	Yes	12	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes

See also

• Content-Type
• Content-Disposition
• GET