What is MIME type "application/x-dfont"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

application/x-dfont is a MIME type that marks a file as a Datafork TrueType font container.
Files of this type hold font data and are mainly used on Mac systems.
They come in files with the DFONT extension.

This format bundles the actual font outlines, metrics, and extra information into one package.
It often includes several variations of a font, such as weight or style, within a single file.

Utilized on Mac platforms for effective font resource management.
Supports multiple font styles gathered in one container.
Ensures proper rendering and scaling of text in applications.
Relies on older resource fork methods familiar to macOS.

For more details on similar font technologies, check out the TrueType standard.

Associated file extensions

.dfont

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/x-dfont

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/x-dfont">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'application/x-dfont');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.dfont

FAQs

What is the application/x-dfont MIME type used for?

The MIME type application/x-dfont classifies a file as a Datafork TrueType font. This format was created by Apple to store font resources in the data fork of a file—rather than the resource fork used in older Mac OS versions—making it safer to transfer across non-Mac networks and file systems.

Can I use .dfont files on my website using CSS?

No, standard web browsers do not support application/x-dfont for web typography. To use the font on a website, you must convert the file to a web-compatible format like WOFF or WOFF2 (see font/woff2) and update your CSS @font-face rules accordingly.

How do I open an application/x-dfont file on Windows?

Windows does not natively recognize or install .dfont files. You will need to use a third-party conversion tool (such as DfontSplitter or an online converter) to transform the file into a standard TrueType (.ttf) or OpenType (.otf) format before installing it via the Windows Control Panel.

How do I configure Apache to serve .dfont files correctly?

To ensure your Apache server sends the correct Content-Type header, add the following line to your .htaccess file or main configuration: AddType application/x-dfont .dfont. This prevents the server from delivering the file as a generic binary stream.

Why does this MIME type start with 'x-'?

The x- prefix indicates that application/x-dfont is a non-standard or private MIME type not officially registered with the IANA. It was defined by Apple specifically for the macOS ecosystem to handle legacy resource-fork structures within a flat file format.

What is the difference between .dfont and .ttf?

While both contain TrueType font data, a .dfont file is a container wrapper specific to macOS that mimics the structure of a resource fork. A standard .ttf file (MIME type font/ttf) is a raw TrueType font file that is universally supported by Windows, Linux, and macOS.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.