What is MIME type "video/x-ms-wm"?

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

The MIME type video/x-ms-wm tells software that the file holds Windows Media video content.
It signals that the file uses Microsoft’s proprietary codecs and container structures.
Files with this type use the ASF container or the WM format.
This information helps media players select the right tools for decoding and playback.

Video Streaming – Used to deliver video over networks.
Playback Support – Recognized by applications like Windows Media Player.
Container Format – Bundles audio, video, and metadata together.

It is especially common in Windows environments where proper codec handling is essential.
For further technical details, see Windows Media on Wikipedia.

Associated file extensions

.asf, .wm

Usage Examples

HTTP Header

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


    Content-Type: video/x-ms-wm

HTML

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


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

Associated file extensions

.asf, .wm

FAQs

Can I play video/x-ms-wm files directly in a web browser?

No, modern web browsers do not natively support the video/x-ms-wm MIME type or the .wm file extension. To display this video on a website, you should convert the file to a widely supported format like video/mp4 or video/webm for use with the HTML5 <video> tag.

How do I configure Apache to serve .wm files correctly?

You can enable support by adding the MIME type definition to your .htaccess file or main configuration. Add the line AddType video/x-ms-wm .wm to ensure the server sends the correct header to the client.

What is the difference between video/x-ms-wm and video/x-ms-wmv?

While both are Microsoft formats based on the ASF container, video/x-ms-wm is typically associated with the generic .wm extension, whereas video/x-ms-wmv is used specifically for .wmv files. Media players usually handle both similarly, but the specific MIME type helps the browser or OS identify the exact file extension used.

Which media players can open files with the video/x-ms-wm MIME type?

Since this is a Microsoft proprietary format, Windows Media Player is the primary application for playback. However, third-party cross-platform players like VLC Media Player also have excellent support for decoding video/x-ms-wm content on macOS and Linux.

Why does my browser download the .wm file instead of playing it?

Browsers force a download when they do not have a built-in codec or plugin to render the content. Because video/x-ms-wm is not part of the standard HTML5 video specification, the browser treats the file as generic binary data.

How do I add video/x-ms-wm support to Nginx?

Open your mime.types file (usually located in /etc/nginx/) and ensure the following line exists inside the types { } block: video/x-ms-wm wm;. If you use the .asf extension with this type, you can modify it to video/x-ms-wm wm asf;.

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.