What is MIME type "image/x-cmx"?

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

The MIME type image/x-cmx identifies files using the CMX format. This format commonly stores vector-based graphics.

It signals to systems and applications that the file holds visual data meant for scalable design. The x- prefix suggests a vendor-specific or experimental type, rather than a universally standard one.

Vector Images: Stores images as scalable graphics.
Legacy Use: Often encountered in older or specialized design software.
File Recognition: Helps applications choose the right tool to open and handle the graphic data.

Additional details can be found at Filext: CMX File Extension.

Associated file extensions

.cmx

Usage Examples

HTTP Header

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


    Content-Type: image/x-cmx

HTML

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


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

Associated file extensions

.cmx

FAQs

Do modern web browsers support image/x-cmx natively?

No, major browsers like Chrome, Firefox, and Safari do not natively render CMX files. If you need to display vector graphics on a website, you should convert the file to SVG (image/svg+xml) or a raster format like PNG.

Which software is required to open files with the image/x-cmx MIME type?

This MIME type is primarily associated with CorelDRAW as it represents the Corel Metafile Exchange format. Other vector editing tools, such as Adobe Illustrator, may also be able to import or convert .cmx files.

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

To ensure your Apache server sends the correct headers for CMX downloads, add the following line to your .htaccess file or server configuration: AddType image/x-cmx .cmx.

What does the "x-" prefix mean in image/x-cmx?

The x- prefix indicates that this is a non-standard or proprietary MIME type not registered in the primary IANA standards tree. It signals that the format is vendor-specific (in this case, belonging to Corel) rather than a universal internet standard.

How do I add support for image/x-cmx in Nginx?

You can add the MIME type definition to your mime.types file or inside the types block of your nginx.conf. Use the following syntax: image/x-cmx cmx;.

Should I use image/x-cmx for web graphics?

Generally, no. Because browsers cannot display it, you should only use image/x-cmx if you intend to offer the file as a downloadable asset for users to edit in desktop software. For visual display, use standard types found on mime-type.com such as JPEG, PNG, or SVG.

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.