With the author Satsuoni's help, the latest DeDRM plugin v10.0.14 for Calibre finally works out. Different from pvevious version of dedrms / no drm fork(v10.0.9), the new released version adds a tool named kfxkeyextractor which is essential for obtaining a cryptographic key from Kindle books downloaded via Kindle for PC V2.8.0.
Though it works for the latest version of Kindle PC app, but the how-to steps are not as simple as before.
Unlock KFX Books Without a Kindle Device
Solution 1. DeDRM V10.0.14 + Kindle for PC V2.8.0
Solution 2. DeDRM V10.0.9 + Kindle for PC V2.4.0
Solution 3. Epubor Ultimate + Kindle for PC V2.8.0 (or Kindle for Mac v7.46)
My Environment: Win 10 64bit, Calibre v8.12, DeDRM v10.0.14, KFX Input v2.27
Step 1. Download the latest version of Calibre for Windows from the official page.
Step 2. Download the latest version of dedrm plugin v10.0.15(released 3 weeks ago, for fixing some k4i generation bugs).
Once finished the downloading, unzip it.
Step 3. Download the latest version of KFX Input plugin v2.27.1. The KFX Input plugin is used for converting KFX format (drm protected kfx will be turned into KFX in calibre) books to other formats such as PDF, ePub, AZW3, DOCX, Mobi, ZIP, etc..
Install the DeDRM_plugin.zip and KFX Input.zip to Calibre Separately
Open Calibre, go to Preferences > Plugins, and click "Load plugin from file." Select the downloaded DeDRM_plugin.zip and confirm the installation.
Repeat the same steps to add KFX Input.zip plugin file to Calibre.
Restart Calibre to finalize both plugins installation, otherwise the plugins won't take effect even though you imported your Kindle books to calibre library successfully.
Copy KFXKeyExtractor28.exe into Kindle App File Location (PC V2.8.0)
Note that the drm plugin v10.0.14(and above) only works for books downloaded via the Kindle for PC V2.8.0 (the latest version released by Amazon Kindle) app.
Download Kindle for PC V2.8.0 here
After finish the installing of kindle pc app, locate the app file location. Then copy the KFXKeyExtractor28.exe from the DeDRM_tools folder to its root directory (typically is c:\Users\<username>\AppData\Local\Amazon\Kindle\application).
Log in to Kindle Library and Download Kindle Books
Be logged in and synchronized in the Kindle pc app. Then, double-click on the book cover to download Kindle books for offline backup.
By default, the downloaded Kindle books will be located under "My Kindle Content" folder (typically is c:\Users\<username>\Documents\My Kindle Content).
Run Command Line to Generate the kindlekey File and k4i File
Get started the Command Prompt(Win+R - execute “cmd”) and run the following utility:
C:\Users\username\AppData\Local\Amazon\Kindle\application\KFXKeyExtractor28.exe "C:\Users\username\Documents\My Kindle Content" kindlekey.txt kindle_account.k4i
assuming that (My Kindle Content) is where your books are stored.
Check that "kindlekey.txt" file is created and not empty. The kindlekey.txt and kindle_account.k4i will be saved under "C:\Users\username\.
Customize DeDRM Plugin and Copy the Extracted Key Files to Calibre
Go into Calibre/ Preferences/ Plugins, and select "DeDRM plugin v10.0.14". Hit "Customize Plugin".
Click on "Kindle for Mac/PC ebooks" and select "Import Existing Keyfiles" icon to add the kindle_account.k4i file.
And then select the textbook icon under "Kindle for Mac/PC ebooks" to copy the kindlekey.txt file there.
Apply the customization and restart Calibre.
Import Kindle Books to Calibre Library and Extract KFX to ePub PDF
Now you can copy the downloaded Kindle book (.azw) from Kindle content folder (My Kindle Content) to Calibre library one by one.
If get a normal "KFX", it means the kindle book's extracting job is finished perfectly. If "KFX-ZIP", it means the processing is failed.
Extracted Kindle Books Appear as KFX-ZIP Files?
When you see "KFX-ZIP"(This Book is Locked by DRM), you should realize that you may have done something wrong during these steps.
- If you added incorrect plugins, you will fail to dedrm.
- If you did not execute the command according to the specified standard command line, you will fail.
- If you get an empty key file, you will fail.
- If you copy the key file and k4i file to wrong places, you will fail.
- Every time you download a new book, you need to repeat the procedure correctly.
In my opinion, when you get kfx-zip error, I highly recommend you update the plugins and re-download Kindle books and extract kindle books again (generate the kindekey text file and kindle_account k4i file). As a better alternative, you can also get a free trial of Epubor Ultimate. There is no need to import and customize the plugins and create essential key files (high risk of failures), and it automatically imports all of the downloaded Kindle books. What's better, whenever you download a new book and you wish to convert it, you only need to sync within epubor ultimate and drag it to the rigt area, no additional steps to customize and recreate new key file. In a word, it is extremely easy and seamless to link, download and extract Kindle to PDF ePub files with literally a few clicks, so that you can access them whenever you need to.
Angel Dan has covered software online marketing for more than 10 years. She joined Epubor since 2013, covering content writing, affiliate marketing, global brand expansion, video marketing, and business development.
Hi, I received an error message when I try to run the extractor key : Qt: Untested Windows version 10.0 detected!
Got offset: 2829bf0
I run Windows 11 pro (in french) so I don't understand why the message speaks about Windows 10... and why it doesn't work. Thank you for your help and sorry for my bad english.
Joëlle
Angeljo
Any mroe problems, please feel free to contact me at epubor.service@gmail.com.
Just a little note: on my PC the 2 key files were generated in C:\Windows\SysWOW64
Great work!
i get this error...(Windows11, Calibre v8.12, DeDRM v10.0.15, KFX Input v2.27)
Found sought after function
Got offset: 29e0000
QObject::startTimer: Timers can only be used with threads started with QThread
DSN 7d7GnJ6nr15bn0nbP7PP6M71t3t576P8tkrJrkn0
Tokens bs4zgmEFYz4dbAgq1/nQVP/Z2k1ADJb+GfDPzTkh/irN3CmADA4cx4BmYnJHR80/8Ow93LjteN3+3dmQ+tMosw==
Fontconfig error: Cannot load default config file
Could not open directory
any advice? thanks in advance!
Please uninstall the DeDRM plugin and run the command again. If it fails, please verify that you have selected the correct directories for both the kindlekeyextractor.exe file and your Kindle content folder.
For a much simpler user experience, we recommend trying Epubor Ultimate.