MIME Types (Reference)

The browser downloads a file instead of displaying it, a stylesheet gets ignored with a MIME warning, or an upload is rejected because the Content-Type does not match: the cause is almost always a wrong MIME type in server config or code. This table gathers 70 common formats, from documents and images to audio, video, fonts and packages, and filters as you type, by extension (.json) or by part of the MIME string (application/json).

On the web the Content-Type header wins, not the file extension: if the server declares text/plain for a .css file, the browser refuses the stylesheet. A few details catch even experienced people: the current type for JavaScript is text/javascript (application/javascript was demoted), .svg only renders as image/svg+xml, and application/octet-stream is the generic type that makes browsers download a file rather than display it.

Use the table when configuring a server (Nginx mime.types, Apache AddType), filling the accept attribute of an upload field or validating Content-Type in an API. Just do not confuse lookup with detection: an extension proves nothing about what is really inside a file; that requires reading its first bytes (magic numbers). The list covers everyday formats, not the full IANA registry, and the search runs entirely in your browser.