The responseType property of the XMLHttpRequest object can be set to change the expected response type from the server. Possible values are the empty string (default), "arraybuffer", "blob", "document", "json", and "text". The response property will contain the entity body according to responseType, as an ArrayBuffer, Blob, Document, JSON, or string. This is null if the request is not complete or was not successful.

AJAX FileReader MIME XMLHttpRequest

API DOM MIME NeedsCompatTable Property Reference Référence

Allows web sites to register themselves as possible handlers for content of a particular MIME type.

API Method MIME Web-Based Protocol Handlers