MIME

Internet media type

An Internet media type, originally called a MIME type after MIME and sometimes a Content-type after the name of a header in several protocols whose value is such a type, is a two-part identifier for file formats on the Internet. The identifiers were originally defined in RFC 2046 for use in e-mail sent through SMTP, but their use has expanded to other protocols such as HTTP, RTP and SIP.

A media type is composed of at least two parts: a type, a subtype, and one or more optional parameters. For example, subtypes of text type have an optional charset parameter that can be included to indicate the character encoding, and subtypes of multipart type often define a boundary between parts.

Types or subtypes that begin with x- are nonstandard (they are not registered with IANA). Subtypes that begin with vnd. are vendor-specific; subtypes in the personal or vanity tree begin with prs..

MIME is short for Multipurpose Internet Mail Extensions, a specification for formatting non-ASCII messages so that they can be sent over the Internet. Many e-mail clients now support MIME, which enables them to send and receive graphics, audio, and video files via the Internet mail system. In addition, MIME supports messages in character sets other than ASCII.

There are many predefined MIME types, such as GIF graphics files and PostScript files. It is also possible to define your own MIME types.

In addition to e-mail applications, Web browsers also support various MIME types. This enables the browser to display or output files that are not in HTML format.

MIME was defined in 1992 by the Internet Engineering Task Force (IETF). A new version, called S/MIME, supports encrypted messages.

List of common media types

IANA manages a registry of media types and character encodings. The organization makes a list available to the public through the Web. Some of the more notable media types used on the Web are listed below:

Type application: Multipurpose files

• application/EDI-X12: EDI X12 data; Defined in RFC 1767
• application/EDIFACT: EDI EDIFACT data; Defined in RFC 1767
• application/javascript: JavaScript; Defined in RFC 4329 but not accepted in IE 8 or earlier
• application/octet-stream: Arbitrary binary. Generally speaking this type identifies files that are not associated with a specific application. Contrary to past assumptions by software packages such as Apache this is not a type that should be applied to unknown files. In such a case, a server or application should not indicate a content type, as it may be incorrect, but rather, should omit the type in order to allow the recipient to guess the type.
• application/ogg: Ogg, a multimedia bitstream container format; Defined in RFC 5334
• application/pdf: Portable Document Format, PDF has been in use for document exchange on the Internet since 1993; Defined in RFC 3778
• application/xhtml+xml: XHTML; Defined by RFC 3236
• application/xml-dtd: DTD files; Defined by RFC 3023
• application/json: JavaScript Object Notation JSON; Defined in RFC 4627
• application/zip: ZIP archive files; Registered

Type audio: Audio

• audio/basic: mulaw audio at 8KHz, 1 channel; Defined in RFC 2046
• audio/mp4: MP4 audio
• audio/mpeg: MP3 or other MPEG audio; Defined in RFC 3003
• audio/ogg: Ogg Vorbis, Speex, Flac and other audio; Defined in RFC 5334
• audio/vorbis: Vorbis encoded audio; Defined in RFC 5215
• audio/x-ms-wma: Windows Media Audio; Documented in Microsoft KB 288102
• audio/vnd.rn-realaudio: RealAudio; Documented in RealPlayer Customer Support Answer 2559
• audio/vnd.wave: WAV audio; Defined in RFC 2361

Type image

• image/gif: GIF image; Defined in RFC 2045 and RFC 2046
• image/jpeg: JPEG JFIF image; Defined in RFC 2045 and RFC 2046
• image/png: Portable Network Graphics; Registered, Defined in RFC 2083
• image/svg+xml: SVG vector image; Defined in SVG Tiny 1.2 Specification Appendix M
• image/tiff: Tag Image File Format; Defined in RFC 3302
• image/vnd.microsoft.icon: ICO image; Registered

Type message

• message/http

Type model: 3D models

Type multipart: Archives and other objects made of more than one part

• multipart/mixed: MIME E-mail; Defined in RFC 2045 and RFC 2046
• multipart/alternative: MIME E-mail; Defined in RFC 2045 and RFC 2046
• multipart/related: MIME E-mail; Defined in RFC 2387 and used by MHTML (HTML mail)
• multipart/form-data: MIME Webform; Defined in RFC 2388
• multipart/signed: Defined in RFC 1847
• multipart/encrypted: Defined in RFC 1847

Type text: Human-readable text and source code

• text/css: Cascading Style Sheets; Defined in RFC 2318
• text/csv: Comma-separated values; Defined in RFC 4180
• text/html: HTML; Defined in RFC 2854
• text/javascript (Obsolete): JavaScript; Defined in and obsoleted by RFC 4329 in order to discourage its usage in favor of application/javascript. However, text/javascript is allowed in HTML 4 and 5 and, unlike application/javascript, has cross-browser support
• text/plain: Textual data; Defined in RFC 2046 and RFC 3676
• text/xml: Extensible Markup Language; Defined in RFC 3023

Type video: Video

• video/mpeg: MPEG-1 video with multiplexed audio; Defined in RFC 2045 and RFC 2046
• video/mp4: MP4 video; Defined in RFC 4337
• video/ogg: Ogg Theora or other video (with audio); Defined in RFC 5334
• video/quicktime: QuickTime video; Registered
• video/x-ms-wmv: Windows Media Video; Documented in Microsoft KB 288102

Type vnd: Vendor Specific File

• application/vnd.oasis.opendocument.text: OpenDocument Text; Registered
• application/vnd.oasis.opendocument.spreadsheet: OpenDocument Spreadsheet; Registered
• application/vnd.oasis.opendocument.presentation: OpenDocument Presentation; Registered
• application/vnd.oasis.opendocument.graphics: OpenDocument Graphics; Registered
• application/vnd.ms-excel: Microsoft Excel files
• application/vnd.ms-powerpoint: Microsoft Powerpoint files
• application/msword: Microsoft Word files
• application/vnd.mozilla.xul+xml: Mozilla XUL files

Type x: Non-standard files

• application/x-www-form-urlencoded Form Encoded Data; Documented in HTML 4.01 Specification, Section 17.13.4.1
• application/x-dvi: Digital Video files in DVI format
• application/x-latex: LaTeX files
• application/x-shockwave-flash: Adobe Flash files; Documented in Adobe TechNote tn_4151 and Adobe TechNote tn_16509
• application/x-stuffit: StuffIt archive files
• application/x-rar-compressed: RAR archive files
• application/x-tar: Tarball files

Type x-pkcs: PKCS standard files

• application/x-pkcs12: p12 files
• application/x-pkcs12: pfx files
• application/x-pkcs7-certificates: p7b files
• application/x-pkcs7-certificates: spc files
• application/x-pkcs7-certreqresp: p7r files
• application/x-pkcs7-mime: p7c files
• application/x-pkcs7-mime: p7m files
• application/x-pkcs7-signature: p7s files

MIME Types By Content Type

Mime Types By File Extension