Content-Type
The Content-Type representation header is used to indicate the original media type of the resource (prior to any content encoding applied for sending).
In responses, a Content-Type header provides the client with the actual content type of the returned content. This header’s value may be ignored, for example when browsers perform MIME sniffing; set the X-Content-Type-Options header value to nosniff to prevent this behavior.
In requests, (such as POST or PUT ), the client tells the server what type of data is actually sent.
| Header type | Representation header |
|---|---|
| Forbidden header name | no |
| CORS-safelisted response header | yes |
| CORS-safelisted request header | yes, with the additional restriction that values can’t contain a CORS-unsafe request header byte: 0x00-0x1F (except 0x09 (HT)), «():<>?@[\]<> , and 0x7F (DEL). It also needs to have a MIME type of its parsed value (ignoring parameters) of either application/x-www-form-urlencoded , multipart/form-data , or text/plain . |
Syntax
Content-Type: text/html; charset=utf-8 Content-Type: multipart/form-data; boundary=something
Directives
The MIME type of the resource or the data.
The character encoding standard. Case insensitive, lowercase is preferred.
For multipart entities the boundary directive is required. The directive consists of 1 to 70 characters from a set of characters (and not ending with white space) known to be very robust through email gateways. It is used to encapsulate the boundaries of the multiple parts of the message. Often, the header boundary is prepended with two dashes and the final boundary has two dashes appended at the end.
Examples
Content-Type in HTML forms
In a POST request, resulting from an HTML form submission, the Content-Type of the request is specified by the enctype attribute on the element.
form action="/" method="post" enctype="multipart/form-data"> input type="text" name="description" value="some text" /> input type="file" name="myFile" /> button type="submit">Submitbutton> form>
The request looks something like this (less interesting headers are omitted here):
POST /foo HTTP/1.1 Content-Length: 68137 Content-Type: multipart/form-data; boundary=---------------------------974767299852498929531610575 -----------------------------974767299852498929531610575 Content-Disposition: form-data; name="description" some text -----------------------------974767299852498929531610575 Content-Disposition: form-data; name="myFile"; filename="foo.txt" Content-Type: text/plain (content of the uploaded file foo.txt) -----------------------------974767299852498929531610575--
Specifications
Browser compatibility
BCD tables only load in the browser
See also
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Common MIME types
This topic lists the most common MIME types with corresponding document types, ordered by their common extensions.
The following two important MIME types are the default types:
- text/plain is the default value for textual files. A textual file should be human-readable and must not contain binary data.
- application/octet-stream is the default value for all other cases. An unknown file type should use this type. Browsers are particularly careful when manipulating these files to protect users from software vulnerabilities and possible dangerous behavior.
IANA is the official registry of MIME media types and maintains a list of all the official MIME types. This table lists important MIME types for the Web:
| Extension | Kind of document | MIME Type |
|---|---|---|
| .aac | AAC audio | audio/aac |
| .abw | AbiWord document | application/x-abiword |
| .arc | Archive document (multiple files embedded) | application/x-freearc |
| .avif | AVIF image | image/avif |
| .avi | AVI: Audio Video Interleave | video/x-msvideo |
| .azw | Amazon Kindle eBook format | application/vnd.amazon.ebook |
| .bin | Any kind of binary data | application/octet-stream |
| .bmp | Windows OS/2 Bitmap Graphics | image/bmp |
| .bz | BZip archive | application/x-bzip |
| .bz2 | BZip2 archive | application/x-bzip2 |
| .cda | CD audio | application/x-cdf |
| .csh | C-Shell script | application/x-csh |
| .css | Cascading Style Sheets (CSS) | text/css |
| .csv | Comma-separated values (CSV) | text/csv |
| .doc | Microsoft Word | application/msword |
| .docx | Microsoft Word (OpenXML) | application/vnd.openxmlformats-officedocument.wordprocessingml.document |
| .eot | MS Embedded OpenType fonts | application/vnd.ms-fontobject |
| .epub | Electronic publication (EPUB) | application/epub+zip |
| .gz | GZip Compressed Archive | application/gzip |
| .gif | Graphics Interchange Format (GIF) | image/gif |
| .htm , .html | HyperText Markup Language (HTML) | text/html |
| .ico | Icon format | image/vnd.microsoft.icon |
| .ics | iCalendar format | text/calendar |
| .jar | Java Archive (JAR) | application/java-archive |
| .jpeg , .jpg | JPEG images | image/jpeg |
| .js | JavaScript | text/javascript (Specifications: HTML and RFC 9239) |
| .json | JSON format | application/json |
| .jsonld | JSON-LD format | application/ld+json |
| .mid , .midi | Musical Instrument Digital Interface (MIDI) | audio/midi , audio/x-midi |
| .mjs | JavaScript module | text/javascript |
| .mp3 | MP3 audio | audio/mpeg |
| .mp4 | MP4 video | video/mp4 |
| .mpeg | MPEG Video | video/mpeg |
| .mpkg | Apple Installer Package | application/vnd.apple.installer+xml |
| .odp | OpenDocument presentation document | application/vnd.oasis.opendocument.presentation |
| .ods | OpenDocument spreadsheet document | application/vnd.oasis.opendocument.spreadsheet |
| .odt | OpenDocument text document | application/vnd.oasis.opendocument.text |
| .oga | OGG audio | audio/ogg |
| .ogv | OGG video | video/ogg |
| .ogx | OGG | application/ogg |
| .opus | Opus audio | audio/opus |
| .otf | OpenType font | font/otf |
| .png | Portable Network Graphics | image/png |
| Adobe Portable Document Format (PDF) | application/pdf | |
| .php | Hypertext Preprocessor (Personal Home Page) | application/x-httpd-php |
| .ppt | Microsoft PowerPoint | application/vnd.ms-powerpoint |
| .pptx | Microsoft PowerPoint (OpenXML) | application/vnd.openxmlformats-officedocument.presentationml.presentation |
| .rar | RAR archive | application/vnd.rar |
| .rtf | Rich Text Format (RTF) | application/rtf |
| .sh | Bourne shell script | application/x-sh |
| .svg | Scalable Vector Graphics (SVG) | image/svg+xml |
| .tar | Tape Archive (TAR) | application/x-tar |
| .tif , .tiff | Tagged Image File Format (TIFF) | image/tiff |
| .ts | MPEG transport stream | video/mp2t |
| .ttf | TrueType Font | font/ttf |
| .txt | Text, (generally ASCII or ISO 8859-n) | text/plain |
| .vsd | Microsoft Visio | application/vnd.visio |
| .wav | Waveform Audio Format | audio/wav |
| .weba | WEBM audio | audio/webm |
| .webm | WEBM video | video/webm |
| .webp | WEBP image | image/webp |
| .woff | Web Open Font Format (WOFF) | font/woff |
| .woff2 | Web Open Font Format (WOFF) | font/woff2 |
| .xhtml | XHTML | application/xhtml+xml |
| .xls | Microsoft Excel | application/vnd.ms-excel |
| .xlsx | Microsoft Excel (OpenXML) | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
| .xml | XML | application/xml is recommended as of RFC 7303 (section 4.1), but text/xml is still used sometimes. You can assign a specific MIME type to a file with .xml extension depending on how its contents are meant to be interpreted. For instance, an Atom feed is application/atom+xml , but application/xml serves as a valid default. |
| .xul | XUL | application/vnd.mozilla.xul+xml |
| .zip | ZIP archive | application/zip |
| .3gp | 3GPP audio/video container | video/3gpp ; audio/3gpp if it doesn’t contain video |
| .3g2 | 3GPP2 audio/video container | video/3gpp2 ; audio/3gpp2 if it doesn’t contain video |
| .7z | 7-zip archive | application/x-7z-compressed |
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This page was last modified on Apr 10, 2023 by MDN contributors.