MIME types

MIME types are standardised names that describe the format of some content. For example, a PDF file uses application/pdf.

The server sends them to the browser in the Content-Type HTTP header, which lets it decide how to process or display the response. A wrong mapping can make a file download, be interpreted incorrectly or be blocked.

In a modern HTML document, the usual meta tag declares the character encoding; it does not replace the MIME type the server sends:

<meta charset="utf-8">

The server must still send that document as text/html; charset=utf-8.

The official reference for registered types is the IANA media types registry.

MIME Types in cPanel lets you map a custom extension to an existing MIME type. This feature is rarely used because the server already includes hundreds of system mappings, which cannot be removed from this interface.

Add a mapping

In cPanel > MIME Types, enter the type and the extension your application needs and save. Do not replace common mappings without knowing what content each file serves; changing the type does not convert its format.

Then open a test file and check Network in the browser's developer tools. Check the Content-Type of the real response, not just the URL's extension. If an application or a CDN responds, its configuration may take precedence over the cPanel mapping.

To undo a mapping of your own, delete it from the list and check again. System mappings cannot be removed from that screen.

If what you need is to run a file as PHP, do not solve it by giving it an arbitrary MIME type: check the PHP interpreter and version. The type describes the response; the handler determines how the file is processed.