What is MIME type "application/x-bentley-dgn"?

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

application/x-bentley-dgn is a MIME type for files created by Bentley MicroStation. These files usually carry the DGN extension and contain vector-based CAD drawing data.

This MIME type tells operating systems and web servers how to handle the file. It ensures that design software opens it correctly and that systems treat it as a CAD file.

Design & Drafting: Stores detailed vector drawing data used in engineering and architectural projects.
Visualization: Supports the display of complex CAD models and diagrams.
Data Exchange: Facilitates the sharing of design files across different systems in collaborative projects.

The non-standard prefix x- shows that it is a proprietary format. This type is central in projects that rely on Bentley’s tools for precise technical drawings.

For further details on Bentley’s CAD systems, visit Bentley Systems.

Associated file extensions

.dgn

Usage Examples

HTTP Header

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


    Content-Type: application/x-bentley-dgn

HTML

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


    <a href="file.dat" type="application/x-bentley-dgn">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-bentley-dgn');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

.dgn

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.