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

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

The MIME type application/x-freemind is used by the FreeMind mind mapping tool. It marks files that contain structured diagrams and plan outlines. These files use an XML format to store ideas hierarchically.
Files using this format come with the file extension MM.

Main use case: Visual brainstorming and idea organization.
Structured data: Captures nodes, links, and annotations.
Collaboration: Helps in planning projects and sharing thoughts.

This MIME type supports free export and import, aiding integration with other diagramming tools. For more details, check the FreeMind project.

Associated file extensions

.mm

Usage Examples

HTTP Header

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


    Content-Type: application/x-freemind

HTML

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


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

Associated file extensions

.mm

FAQs

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

The MIME type application/x-freemind is associated with FreeMind, a free mind-mapping application written in Java. It identifies files, typically with the .mm extension, that contain hierarchical information and diagram structures stored in XML format.

How do I configure an Apache server to serve .mm files correctly?

To ensure browsers handle FreeMind files correctly, add the line AddType application/x-freemind .mm to your .htaccess file or your main Apache configuration. This prevents the server from delivering the file as generic text/xml or text/plain.

Why does my browser show XML code when I click a FreeMind link?

Most web browsers (like Chrome or Firefox) do not natively render application/x-freemind diagrams. Since the underlying format is XML, the browser defaults to displaying the raw code tree. To view the map visually, you must download the file and open it in the FreeMind desktop application.

What is the correct Nginx configuration for FreeMind files?

In Nginx, you should locate your mime.types file and ensure it includes the entry application/x-freemind mm;. If you cannot edit the global types, you can add types { application/x-freemind mm; } inside the specific server or location block of your config.

Can I open application/x-freemind files in other software?

Yes, because the format is an open XML standard, other mind-mapping tools like Freeplane and XMind can often import these files. Additionally, simply renaming the file to .xml allows it to be viewed in any text editor, though you will lose the visual diagram representation.

Is application/x-freemind a standard IANA MIME type?

No, the x- prefix indicates that it is a non-standard or experimental subtype (x-freemind). While it is not officially registered in the IANA main registry, it is the de facto standard used by the FreeMind software and community to identify mind map files.

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.