The output will appear here...
This is an in-browser data-uri generator. Technically any file can be converted into a base64 data URI.
However, the browser will only give you MIME types for supported file types. All common image (jpg, png), audio (mp3, wav, ogg, acc) & video files should work just fine.
Big files will take some time to be converted and it's not really recommended to load a big file as a data-url as it's inefficient.