What is MIME type "text/x-opml"?

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

text/x-opml is a MIME type for files using the Outline Processor Markup Language (OPML) 2.0. It formats outlines and hierarchies using plain text with XML structure.

This type is common in applications that exchange structured lists. It lets programs import/export data like RSS feed subscriptions and organized tasks.

The main use is exchanging outline data between different applications.
It is used in news aggregators for managing RSS feeds.
It supports mind mapping and project planning by maintaining a clear hierarchy.

Files in this format are stored as XML, making them both human-readable and easy for machines to process. They are usually seen with the OPML extension.

For more technical details, check out the OPML entry on Wikipedia.

Associated file extensions

.opml

Usage Examples

HTTP Header

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


    Content-Type: text/x-opml

HTML

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


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

Associated file extensions

.opml

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.