What is MIME type "application/vnd.openxmlformats"?

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

The MIME type application/vnd.openxmlformats signals that a file follows the Office Open XML standards. It tells programs and browsers how to read and process the file's contents.

Files like the macro-enabled PowerPoint, for example PPTM, carry extra code (macros) that adds automation and interactivity.

This MIME type uses an XML structure inside a compact container. That approach makes the file flexible and easier to update. It also assists in ensuring compatibility across different applications and operating systems.

File identification: It provides clear instructions so software can properly open and display the document.
Data structure: It organizes content, formatting, and macros using XML, a well-known markup language.
Modern standard: It is part of the unified, open standard adopted by many Office applications.

For more details on the format and its technical background, visit the Office Open XML page.

Associated file extensions

.pptm

Usage Examples

HTTP Header

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


    Content-Type: application/vnd.openxmlformats

HTML

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


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

Associated file extensions

.pptm

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.