The HTTPContent-Typerepresentation header is used to indicate the originalmedia type of a resource before any content encoding is applied.

In responses, theContent-Type header informs the client about the media type of the returned data.In requests such asPOST orPUT, the client uses theContent-Type header to specify the type of content being sent to the server.If a server implementation or configuration is strict about content type handling, a415 client error response may be returned.

TheContent-Type header differs fromContent-Encoding in thatContent-Encoding helps the recipient understand how to decode data to its original form.

* Values can't contain aCORS-unsafe request header byte:"():<>?@[\]{},, Delete0x7F, and control characters0x00 to0x19 except for Tab0x09.It also needs to have a media type of its parsed value (ignoring parameters) of eitherapplication/x-www-form-urlencoded,multipart/form-data, ortext/plain.

Syntax

Content-Type: <media-type>

For example:

Content-Type: text/html; charset=utf-8Content-Type: multipart/form-data; boundary=ExampleBoundaryString

Directives

<media-type>

Themedia type of the resource or data.May contain the following parameters:

• charset: Indicates thecharacter encoding standard used.The value is case insensitive but lowercase is preferred.
• boundary: For multipart entities, theboundary parameter is required.It is used to demarcate the boundaries of the multiple parts of the message.The value consists of 1 to 70 characters (not ending with white space) known to be robust in the context of different systems (e.g., email gateways).Often, the header boundary is prepended by two dashes in the request body, and the final boundary has two dashes appended at the end.

Examples

Serving assets with correct content type

In the following two example responses, JavaScript and CSS assets are served usingtext/javascript for JavaScript andtext/css for CSS.The correct content type for these resources helps the browser handle them more securely and with better performance.SeeProperly configuring server MIME types for more information.

HTTP/1.1 200content-encoding: brcontent-type: text/javascript; charset=utf-8vary: Accept-Encodingdate: Fri, 21 Jun 2024 14:02:25 GMTcontent-length: 2978const videoPlayer=document.getElementById...

HTTP/3 200server: nginxdate: Wed, 24 Jul 2024 16:53:02 GMTcontent-type: text/cssvary: Accept-Encodingcontent-encoding: br.super-container{clear:both;max-width:100%}...

Content-Type in multipart forms

In aPOST request resulting from an HTML form submission, theContent-Type of the request is specified by theenctype attribute on the<form> element.

<form action="/foo" method="post" enctype="multipart/form-data">  <input type="text" name="description" value="Description input value" />  <input type="file" name="myFile" />  <button type="submit">Submit</button></form>

The request looks something like the following example with some headers omitted for brevity.In the request, a boundary ofExampleBoundaryString is used for illustration, but in practice, a browser would create a string more like this---------------------------1003363413119651595289485765.

POST /foo HTTP/1.1Content-Length: 68137Content-Type: multipart/form-data; boundary=ExampleBoundaryString--ExampleBoundaryStringContent-Disposition: form-data; name="description"Description input value--ExampleBoundaryStringContent-Disposition: form-data; name="myFile"; filename="foo.txt"Content-Type: text/plain[content of the file foo.txt chosen by the user]--ExampleBoundaryString--

Content-Type in URL-encoded form submission

When forms don't involve file uploads and are using simpler fields, URL-encoded forms may be more convenient where the form data is included in the request body:

<form action="/submit" method="post">  <label for="comment">Comment:</label>  <input type="text" name="comment" value="Hello!" />  <button type="submit">Submit</button></form>

POST /submit HTTP/1.1Host: example.comContent-Type: application/x-www-form-urlencodedContent-Length: 15comment=Hello!

Content-Type in a REST API using JSON

ManyREST APIs useapplication/json as a content type which is convenient for machine-to-machine communication or programmatic interaction.The following example shows a201 Created response showing the result of a successful request:

HTTP/1.1 201 CreatedContent-Type: application/json{  "message": "New user created",  "user": {    "id": 123,    "firstName": "Paul",    "lastName": "Klee",    "email": "p.klee@example.com"  }}

Specifications

Browser compatibility

See also

• Accept,Accept-Encoding,Accept-Language headers
• Vary
• Content-Encoding
• Content-Disposition
• 206 Partial Content
• X-Content-Type-Options