MIME multipurpose Internet mail extensions MIME has absolutely nothing to do with Marcel Marceau. It's a way to extend the power of Web browsers to handle graphics, sound, multimedia--anything but text. (Remember, HTML handles nothing but text--everything else is an extension.) MIME is also used for binary email attachments. Browsers recognize MIME types in categories and file types, separated by a slash (such as image/gif). If you've registered a MIME type, the browser decodes the file and launches a helper application. See also: helper applications, HTML, viewer