PDF to RTF

The file is uploaded to our server because it's necessary to process it with Calibre, but it's deleted immediately after the conversion.

It works best with text-based PDFs. With scanned documents the result may be poor, since Calibre needs to be able to read the content.

Typically a few seconds.

Because generating an editable RTF from a PDF requires Calibre, which can only run on a server.

Yes, RTF is a format compatible with virtually any word processor, from Word to free alternatives.

Usually a few seconds, though it may vary depending on the file size and server load at that moment.