Although it is not wrong to tell people how to remove the DRM ( ie: this post is not wrong), we are not condoning piracy: we do not recommend you strip off the DRM and share/sell the books in violation of copyrights laws. Use Calibre to remove DRM only when you are certain that you have the rights to read the books anywhere and in however formats that you want.

What changes Amazon did recently:

Starting from Kindle App 1.19 onwards, Amazon changes the format of the downloaded Kindle ebooks to KFX format. The direct consequence of this action is that Calibre ( with DeDRM plugin) that many people love to use, can no longer strip the DRM off from Amazon ebooks , and can no longer convert the Kindle ebooks to MOBI or EPUB format. To quote a post from Mobileread forum:

These books will appear in a subdirectory of the “My Kindle Content” folder, will import into calibre as “AZW” format, and will fail to convert with the error: “KFXError: This is an Amazon KFX book. It cannot be processed.”

The post goes on to suggest how one can workaround this issue. Techniques mentioned:

  1. Never upgrade to later version of Kindle App, stick with 1.19
  2. Disable KFX support on Kindle App

Those techniques are not straightforward, and require technical expertise to properly configure your software. Won’t it be better if someone just make the DeDRM works with the latest KFX formats?

And finally, the DeDRM 6.6.1 is now here…

Thanks to the work of Apprentice Alf and some other people, DeDRM 6.6.1 can decrypt Amazon KFX format! We have tested the solution and it really works!.

What you need to do:

  1. Update the Kindle App to the latest version. No need to stick to 1.19. Anyway Amazon turns on auto update by default. [Update: Jan 23, 2019: DRM removal for KFX format only works with eBooks from Downloaded from Kindle for PC/Mac versions 1.19 through 1.24.3]
  2. Update the Calibre to the latest version. This is just to make sure that Calibre can support whatever plugins that come along
  3. Install the KFX Input plugin, by following the guide here.
  4. Install the latest DeDRM 6.6.1, you can download the plugin files here.
  5. Download a Kindle ebook to your PC via Kindle App
  6. Drag the book into the Calibre
  7. Convert the book from AZW to MOBI ( or any other format).
  8. Now you can read the book at anywhere that you like!

Happy reading!