The Complete List of MIME Types

What is MIME TYPE?

1. First, we need to understand how browsers process content. The content displayed in the browser includes HTML, XML, GIF, and Flash... So, how does the browser distinguish them and decide what content to display in what form? The answer is MIME Type, which is the media type of the resource.

The media type is usually told to the browser by the web server through the HTTP protocol, more precisely, through Content-Type, for example:

Content-Type: text/HTML

Indicates that the content is of type text/HTML, that is, a hypertext document. Why "text/HTML" and not "HTML/text" or something else? MIME Type is not specified by individuals, but is negotiated by the ietf organization and published on the Internet in the form of RFC as a recommended standard. Most web servers and user agents support this specification (by the way, the type of email attachments is also specified by MIME Type).

Usually only some formats that are widely used on the Internet will have a MIME Type. If it is a format defined by a client, it can generally only start with application/x-.

XHTML is a widely used format. Therefore, RFC 3236 states that the MIME Type of XHTML format files should be application/xHTML+XML.

Of course, when processing local files, if no one tells the browser the MIME Type of a file, the browser will also do some default processing, which may be related to the MIME Type you configured for the file in the operating system. For example, under Windows, open the registry key "HKEY_LOCAL_MACHINESOFTWAREClassesMIMEDatabaseContent Type" and you can see the configuration information of all MIME Types.

Second, when the output results are transmitted to the browser, the browser must launch the appropriate application to process the output document. This can be done using various types of MIME (Multipurpose Internet Mail Extensions). In HTTP, the MIME type is defined in the Content-Type header.

For example, suppose you want to send a Microsoft Excel file to a client. Then the MIME type at this time is "application/vnd.ms-excel". In most practical cases, this file will then be passed to Execl for processing (assuming we set Execl as the application to handle the specific MIME type). In ASP, the method to set the MIME type is through the ContentType property of the Response object.

Multimedia file format MIME

In the earliest HTTP protocol, there was no additional data type information. All transmitted data was interpreted by the client program as Hypertext Markup Language HTML documents. In order to support multimedia data types, the HTTP protocol used MIME data type information attached to the document to identify the data type.

MIME stands for Multi-purpose Internet Mail Extensions. It was originally designed to attach multimedia data when sending emails so that email clients can process them according to their type. However, when it is supported by the HTTP protocol, its significance becomes more significant. It makes HTTP transmission more than just ordinary text, but also rich and colorful.

Each MIME type consists of two parts. The first part is the general category of data, such as audio, image, etc., and the second part defines the specific type.

Common MIME types

Hypertext Markup Language text.html,.html text/html
Plain text.txt text/plain
Rich Text .rtf application/rtf
GIF graphics.gif image/gif
JPEG graphics .ipeg, .jpg image/jpeg
au sound file.au audio/basic
MIDI music file mid,.midi audio/midi,audio/x-midi
RealAudio music files .ra, .ram audio/x-pn-realaudio
MPEG files .mpg, .mpeg video/mpeg
AVI file.avi video/x-msvideo
GZIP file.gz application/x-gzip
TAR file.tar application/x-tar

There is a special organization IANA on the Internet to confirm standard MIME types, but the Internet is developing too fast and many applications cannot wait for IANA to confirm that the MIME types they use are standard types. Therefore they use the method of starting the category with x- to indicate that this category has not yet become a standard, for example: x-gzip, x-tar, etc. In fact, these types are so widely used that they have become de facto standards. As long as the client and server both recognize the MIME type, it does not matter even if it is a non-standard type. The client program can use specific processing methods to process the data based on the MIME type. In Web servers and browsers (including operating systems), standard and common MIME types are set by default. Only for uncommon MIME types do you need to set up both the server and the client browser for identification.

Since the MIME type is related to the document suffix, the server uses the document suffix to distinguish the MIME types of different files. The correspondence between the document suffix and the MIME type must be defined in the server. When the client program receives data from the server, it only receives the data stream from the server and does not understand the name of the document, so the server must use additional information to tell the client program the MIME type of the data. Before sending the actual data, the server will first send the MIME type information that identifies the data. This information is defined using the Content-type keyword. For example, for an HTML document, the server will first send the following two lines of MIME identification information. This identification is not part of the actual data file.

Content-type: text/html

Note that the second line is a blank line, which is required. The purpose of using this blank line is to separate the MIME information from the actual data content.

MIME (Multipurpose Internet Mail Extensions) is an Internet standard for describing message content types.
MIME messages can contain text, images, audio, video, and other application-specific data.
Official MIME information is provided by the Internet Engineering Task Force (IETF) in the following document:
RFC-822 Standard for ARPA Internet text messages

RFC-2045 MIME Part 1: Format of Internet Message Bodies
RFC-2046 MIME Part 2: Media Types
RFC-2047 MIME Part 3: Header Extensions for Non-ASCII Text
RFC-2048 MIME Part 4: Registration Procedures
RFC-2049 MIME Part 5: Conformance Criteria and Examples
Different applications support different MIME types.