The HTTP
POST method 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 (usemultipart/form-datainstead)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 theContent-Dispositionheader 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.
| Request has body | Yes |
|---|---|
| Successful response has body | Yes |
| Safe | No |
| Idempotent | No |
| Cacheable | Only if freshness information is included |
| Allowed in HTML forms | Yes |
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=value2A 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
| Specification | Title |
|---|---|
| RFC 7231, section 4.3.3: POST | Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content |
| RFC 2046, section 5.1.1: Common Syntax | Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types |
Browser compatibility
Update compatibility data on GitHub
| Yes | 12 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Legend
- Full support