How to Remove DRM from KFX-ZIP Files?

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Many ebook enthusiasts prefer using Calibre to organize, convert, and manage their eBooks in various formats. If you own Kindle books, you might encounter a situation where the resulting format of your Kindle KFX files becomes KFX-ZIP after importing them to Calibre. Consequently, you can neither convert nor open this KFX-ZIP file in Calibre due to DRM protection. To use this file for backup purposes or personal uses, DRM removal is necessary. In this tutorial, you will learn how to remove DRM from the KFX-ZIP files.

kfx zip in calibre

1. What is the Difference between KFX and KFX-ZIP File?

First things first, you will only encounter a KFX-ZIP file in Calibre. Books in KFX format delivered by Amazon are a bundle of files composed of an encrypted main container, a metadata container, a DRM voucher, and auxiliary containers (zero or more). Each of these contains only a part of the book's content and cannot be converted individually. KFX container files typically have a '.kfx' extension, though other extensions ('.azw', '.azw8', and '.azw9') are used by some software.

Generally speaking, Kindle KFX files are DRM-encrypted.

However, after importing a Kindle KFX file into Calibre, if the resulting format is KFX, it indicates that this file is DRM-free now. If the resulting format is KFX-ZIP, then DRM removal has failed. Therefore, a DRM Removal tool is needed to get rid of DRM.

2. Why You will Get KFX-ZIP File?

When you add Kindle KFX books to Calibre, you will come across a KFX-ZIP file only if you have installed the KFX Input plugin, and no functional DeDRM plugin is installed in Calibre. Why did this happen? The reasons are as follows:

If the KFX Input plugin is installed, it converts the book from KFX to KFX-ZIP upon import. Typically, the next step involves the DeDRM plugin (if installed) removing any DRM. The KFX Input plugin then converts the KFX-ZIP back to KFX. However, in this case, the DeDRM plugin is not installed, and DRM cannot be removed. Consequently, the KFX Input plugin does not convert KFX-ZIP back to KFX. Therefore, the resulting format in Calibre is KFX-ZIP.

3. How to Remove DRM from KFX-ZIP Files?

In Calibre, users can leverage two powerful plugins: the DeDRM plugin and the KFX Input plugin. The DeDRM plugin is specifically designed for removing DRM, while the KFX Input plugin is utilized for importing DRM-free KFX books into Calibre. It enables users to manage and convert these DRM-free KFX books to various formats, including PDF. Below are detailed steps to remove KFX DRM using the Calibre plugin:

Step 1Download and Install Calibre.

Ensure you have Calibre installed on your computer.

Step 2Download DeDRM Plugin and KFX Input Plugin.

Download both the DeDRM plugin and KFX Input plugin from the official repository.

Make sure to unzip the DeDRM_tools plugin package before trying to load it into Calibre. Failure to do so may result in encountering the following error.

fail to load dedrm plugin

Step 3Install DeDRM Plugin and KFX Input Plugin.

Open Calibre. Navigate to "Preferences" > "Plugins." Click on "Load plugin from file" and select the DeDRM plugin and click "Open".

load dedrm plugin to calibre

Next, click "OK" in the following pop-up alert window and click "Restart calibre now" for the plugin to take effect. And repeat the same steps to load and KFX Input plugin into Calibre(Don't unzip the KFX Input plugin package).


Using the DeDRM (version 10.0.9 beta) and KFX Input plugins installed in calibre, it is possible to import into calibre and convert the vast majority of books downloaded via the latest Kindle for PC (version 2.x.x) or Kindle Classic for Mac (version 1.40.2). However, so far Amazon has also used the newer, unbroken DRM for a select set of books(usually come with .kcr extension) that require the strongest encryption. In this case, please use Epubor Kindle Converter to remove DRM from Kindle KCR books.

Download Epubor Kindle Converter for Free


convert kindle books successfully android on mac

Step 4Add KFX Books to Calibre.

Click on "Add books" in Calibre and select the KFX files. Alternatively, you can simply drag and drop the KFX files into calibre. Ensure that the resulting format is KFX, confirming the successful removal of DRM.

drm free kindle kfx files

Step 5[Optional]Convert KFX to Other Formats.

The KFX Input plugin for Calibre is essential for the conversion task. Once you've installed the KFX Input plugin in Step 3, converting DRM-free KFX books to your desired format is straightforward. Simply click on "Convert books", then select your preferred output format.

convert drm free kfx file

Download Epubor Kindle Converter for Free



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03/6/2024 06:36:44
Thank you so very much!  This was exactly what I needed, and explained EXACTLY as easy as I needed it to be.  THANK YOU.
03/6/2024 08:40:47
Thank you for your feedback. We are pleased to learn that the post was helpful to you.
04/7/2024 19:34:18
the link for KFX Input Plugin doesn't work
04/8/2024 08:59:03
Thank you for your comments. We've updated the link.
06/9/2024 18:27:30
Followed all this and it will nor convert the KFX file. Any other ideas
06/11/2024 09:46:01
Thank you for your comments. If you cannot convert the kindle kfx with calibre, please try to use Epubor Ultimate. It will help you remove drm from kindle kfx ebooks. Please feel free to contact us via support@epubor.com if you need any further assistance.
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