Uploaded files are processed on our own conversion servers, nobody looks at them, and they are not shared. The upload and the converted file are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
Free conversions have a size limit per file, set by the type of file, and the page tells you when a file is over it. A paid plan removes that limit, so much larger files can be converted.
