What is MIME type "image/t38"?

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

The MIME type image/t38 is used for transmitting fax images over IP networks. It relies on the T.38 protocol to send fax data digitally rather than over traditional phone lines.

This type is not meant for photos or typical graphics. Instead, it ensures fax information travels reliably over a network. It is common in fax over IP and VoIP systems, consolidating fax machines with modern communication platforms.

Used for real-time fax transmission over the internet
Relies on the T.38 standard for validation
Helps merge traditional faxing with digital voice networks
Supports digital fax communication in various unified systems

Files associated with this MIME type usually carry the extension T38.

For more technical details, check out the T.38 standard.

Associated file extensions

.t38

Usage Examples

HTTP Header

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


    Content-Type: image/t38

HTML

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


    <a href="file.dat" type="image/t38">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/t38');
      res.end('Content here');
    }).listen(3000);

Associated file extensions

.t38

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.