Dealing with Kindle ebooks in calibre

[lkmiller]

Originally Posted by madelonw

There were more than one firmware updates that disabled my process. I no longer worry about the KFX-ZIP problem because (apparently) there is nothing to be done with these files going forward (at least as far as getting usable files into Calibre).

There is if you use the free tools available instead.

[Jadehawk]

I never used Epubor, but with permission from Satsuoni, I started using a python script as a wrapper for K4PC (since Jul 2025) and eventually also for MSIX and Android Kindle app versions.

Now I have merged them into a single app (spares user having to install python), makes it much easier to maintain (for me) and allows me to help other users troubleshoot when they can't get Satsuoni's tools working in their setups.

It may not be as fancy as what Epubor may provide but is functional for non-techy users and there is no fee to use it.

I made this ultimately for me as a one click, Extractor + Import (To Calibre) + Convert (Using Calibre and KFX-Input plugin).

This is overkill for sure, 100% not needed, but some may find it useful.

What ppl may not like:

• Needs registration on blog (free, no ads, no mailing list, no contact from me, not selling email addresses) (This prevents unwanted bots scraping the site, specially for Amazon related content and reduces Hot-Linking ).
• Uses email to activate app (App talks to my server and allows to serve the correct Satsuoni extractor needed by the user, as well as provide updated extractor when released, also missing DLL's when needed for Fallback)