What is MIME type "application/x-ms-multiplan"?

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-ms-multiplan identifies files made for Microsoft's legacy MultiPlan spreadsheet program. These files use the format reserved for data created in old MultiPlan applications and are not common on modern systems.

When you see this MIME type, it means the file holds spreadsheet data arranged in a proprietary format. The file extension linked to it is MOD, which can help software or operating systems determine how to process the file.

For further details on MIME types and their roles, visit the MDN Web Docs on MIME types.

Associated file extensions

.mod

Usage Examples

HTTP Header

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


    Content-Type: application/x-ms-multiplan

HTML

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


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

Associated file extensions

.mod

FAQs

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

The MIME type application/x-ms-multiplan represents files created by Microsoft MultiPlan, an early spreadsheet program that predates Excel. It specifically identifies data stored in the MultiPlan format, which is distinct from modern .xlsx or .csv files.

How do I open a file sent as application/x-ms-multiplan?

Because MultiPlan is obsolete, you cannot open these files with standard modern web browsers. You may be able to import the file into Microsoft Excel using legacy file support options, or use a specialized file converter to transform the data into a readable format.

Why is my .mod audio file being detected as application/x-ms-multiplan?

The .mod extension is ambiguous; it is used for both MultiPlan spreadsheets and Amiga music modules. If your server is misconfigured, it might assign the spreadsheet MIME type to your music files. For audio, the correct type should generally be audio/x-mod or audio/mod.

How do I configure Apache to serve MultiPlan files correctly?

To ensure Apache serves the correct header for these legacy spreadsheets, add the following line to your .htaccess file or main configuration: AddType application/x-ms-multiplan .mod. This prevents browsers from confusing the file with plain text or audio.

How do I set the correct MIME type for .mod files in Nginx?

In your nginx.conf or the mime.types file, include the directive: application/x-ms-multiplan mod;. However, if you are hosting music files instead of spreadsheets, ensure you use the appropriate audio MIME type to avoid playback issues.

Is application/x-ms-multiplan safe to open?

Legacy binary formats like this are generally inert data, but opening them in outdated software can sometimes pose security risks due to unpatched vulnerabilities. Always scan files with the /file-extension/mod/ extension for malware before opening them on a production system.

What does the 'x-' prefix mean in application/x-ms-multiplan?

The x- prefix indicates that this is a non-standard or experimental MIME type that was not registered with the IANA at the time of its creation. It signifies a proprietary format defined by Microsoft (ms) for the MultiPlan software.

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.