Dealing with Kindle for PC/Mac 1.19 and KFX in calibre

[jhowell]

It is possible to import into calibre and convert the vast majority of books downloaded using the latest release of Kindle for PC (version 2.3.5) or Kindle Classic for Mac (version 1.40.3) as long as both the DeDRM (version 10.0.9 beta) and KFX Input plugins are installed in calibre.

Some books that Amazon always delivers with the strongest encryption may not work when downloaded using these programs, however no other method is likely to work for those books anyway.

The newer Kindle for PC app available in the app store for Windows 11 and the latest Kindle for Mac app (7.0 and later) cannot be used to download usable books.

Most books downloaded using the PC/Mac apps will be in KFX format. This format is highly processed by Amazon. In most cases KF8 (azw3) format is closer to the original file format provided to Amazon by the publisher. Users who desire that format should use other methods.

For methods of obtaining usable Kindle books that do not involve the PC and Mac apps see the threads Amazon and DRM changes and DRM workaround: Kindle for Android.

Older methods that no longer apply in most cases have been moved to the following spoiler.

Spoiler:

Important update: Amazon has made a change to their service so the books published since Jan 3 2023 can no longer be downloaded using Kindle for PC or Mac versions prior to 1.39. (Details in this thread.)This means that methods 1, 2, and 4 described below are no longer effective for those books. Methods 3 and 5 still work. There is also a new method (#6) using an old version of the Kindle for Android app described here.

The Kindle for PC and Kindle for Mac programs use Amazon's KFX format for most books. Each book will appear in a separate subdirectory of the "My Kindle Content" folder with a file extension of ".azw". Unless additional steps are taken, these books will fail to convert in calibre with the error: "KFXError: This is an Amazon KFX book. It cannot be processed."

There are several methods for either avoiding or handling KFX format. The following descriptions apply both to Kindle for PC and Kindle for Mac unless one is mentioned explicitly.


Method 1 - Revert to an older version of Kindle for PC/Mac

Older Kindle for PC/Mac version 1.17 can sometimes be installed to work around this problem. (Note: This is a 32-bit program and so it is not compatible with MacOS Catalina and later.)

Perform the following steps:

• Launch Kindle and under the menu choice "Tools", "Options", "General", uncheck "Automatically install updates when they are available without asking me.", and save. (Note: This option is not available in some Kindle for Mac versions.)
• Exit the Kindle program.
• Delete the contents of the "My Kindle Content" folder within your "Documents" folder.
• Download and verify version 1.17 of Kindle for PC/Mac. (See instructions later in this post.)
• Install the downloaded version 1.17 software.
• Launch it and check that the option to automatically install updates is still turned off.
• Kindle may need to be registered by signing in to your Amazon account within the program. Some users have reported being unable to sign in to their Amazon account within Kindle for PC once version 1.17 is reinstalled. If that occurs go to the Amazon website and on the manage your content and devices page, and on the "Your Devices" tab locate "Kindle for PC" (or Mac) and deregister it using the "..." "Actions" menu. Wait a few minutes for it to take effect and try to sign in again. (If all else fails then re-install and register again and start over with step 1.)
• Re-download your books before importing into calibre.
• If asked if you want to update to the new version always reject it. (Choose "Skip this version".)
• Kindle may try to update itself without asking for permission. See the end of this post for ways to prevent undesired updating of the Kindle app.

Method 2A - Disable KFX support in Kindle for PC at startup

It is possible to prevent versions of Kindle for PC up to version 1.34 from making use of KFX format by using a special batch file to launch the program. (This method does not apply to Kindle for Mac or to Kindle for PC version 1.35 and later.)

KFX_begone4.bat can be downloaded from this post. (Thanks to DNSB.) When launched this batch file will start Kindle for PC and then apply a registry change to disable KFX format. The batch file may take several seconds to terminate. After that any books downloaded using Kindle for PC will be in the older Kindle formats.

If a book downloads while the batch file is in progress it may be delivered in KFX format. If that happens remove the book and download it again.

If Kindle for PC is started without using KFX_begone4 it will revert to allowing KFX. The batch file must always be used to launch Kindle for PC before downloading books.


Method 2B - Disable KFX support in Kindle for PC/Mac

It is possible to prevent some older versions of Kindle for PC/Mac from making use of KFX format by applying a change to the software.

The last Kindle for PC version in which KFX can be disabled using the method described below is 1.24.3 (51068) and the last Kindle for Mac version is 1.31. It will not work if a later version is installed.

Perform the following steps:

• Exit the Kindle program.
• Open a command window (PC) or terminal window (Mac).
• Cut and paste the appropriate command for your operating system to disable the renderer-test program.
  PC:
  ren %localappdata%\Amazon\Kindle\application\renderer-test.exe renderer-test.xxx
  Mac:
  chmod -x /Applications/Kindle.app/Contents/MacOS/renderer-test
  This prevents the renderer-test program from executing, blocking the use of KFX.
  
  PC Note: The renderer-test program may be in a different location in some Kindle for PC installations. If the rename command fails look in other folders, such as C:\Program Files\Amazon\Kindle.
  
  Mac Note: If the chmod command fails with a permission error try again using sudo.
  
• After restarting the Kindle program any books previously downloaded in KFX format will no longer open. You will need to remove them from your device and re-download them. All future downloads will use the older Kindle formats instead of KFX although they will continue to be placed in one individual subdirectory per book.
• See the post by odamizu for additional instructions required when using Kindle for Mac 1.25.2 or later. (link)
• If the Kindle software is updated or re-installed these steps will need to be repeated. See the end of this post for ways to prevent undesired updating of the Kindle app.

Method 3 - Use an e-ink Kindle instead

If you have an e-ink Kindle device registered to your Amazon account you have the option of downloading books directly from Amazon instead of using Kindle for PC/Mac.

• From the Amazon website access "Account & Lists" -> "Manage Your Content and Devices".
• Find a book you want to import into calibre and press the "..." button in the "Actions" column for that book.
• In the menu that pops up choose "Download & transfer via USB". Then select the name of your registered kindle device in the drop down menu and press the "Download" button.
• Import the downloaded file into calibre using the same procedure that you would use for a file from Kindle for PC. You will need to select the proper folder containing the downloaded file. (This folder will be different from the "My Kindle Content" folder used by Kindle for PC.)

Note that Download & Transfer is not available for every book. Books borrowed through Kindle Unlimited or Prime Lending do not have this option. And there are other miscellaneous categories of books where this is unavailable.

In addition, the owners of older e-ink Kindles running firmware prior to 5.6.5 (August 2015) can access books in non-KFX formats directly from the device via USB.


Method 4 - Convert from KFX to other formats

It is possible to convert books from KFX to other formats in calibre by installing the optional KFX Input plugin. This can be useful for books that are only available in KFX format, such as those in Arabic and Traditional Chinese.

Using the most recent pre-release version of the DRM removal plugin (10.0.9) it is possible to removal KFX DRM from books downloaded using certain versions of Kindle for PC (up to version 2.0) and Kindle for Mac (up to version 1.40.1).

Amazon is aggressive in updating KFX DRM whenever it is broken so anyone desiring to do this should act quickly. Newer versions of these app with new DRM are in the process of being rolled out.

Method 5 - Choose books not available in KFX format

Books that are unavailable in KFX format will be delivered to Kindle for PC in Amazon's older formats for which DRM removal is possible. Unfortunately these are only a very small subset of the Kindle books available on Amazon and it is difficult to tell ahead of time which books they are. For those books this works using even the latest version of Kindle for PC.

Many comics and manga should work. If the product description of a book shows "Enhanced typesetting: Enabled" then that book will almost certainly not work.

You can obtain the free sample of a prospective book and test whether that works before purchasing. However there will be cases when a sample is not delivered in KFX format but the full book is. If you download the book and there is a "voucher" file present then it is in KFX format.


Method 6 - Use an old version of Kindle for Android

The Kindle for Android app can be run using emulator software on just about any system. An Android device is not required.

See the thread: DRM workaround: Kindle for Android for details.


**********************************************
Obtaining and verifying older versions of Kindle for PC/Mac software

Older versions of the Kindle PC/Mac software are no longer available directly from Amazon. You will need to search online for the proper file name and download it from a third party site. The file name to search for each version is listed below.

Important: After downloading you should verify the SHA-256 hash of the file in order to avoid malware. If the hash does not match, delete the downloaded file and try again from another site. Do not install a file that has an incorrect hash!

One way to verify a hash in Windows is to open a command window, change to the folder containing the downloaded program, and enter the command:
certutil -hashfile <filename> SHA256

In MacOS use the command:
shasum -a 256 <filename>

(Replace <filename> with the actual name of the downloaded file.)


version 1.17/1.17.1
filename: KindleForPC-installer-1.17.44170.exe
SHA-256: 14e0f0053f1276c0c7c446892dc170344f707fbfe99b695176 2c120144163200

filename: KindleForMac-44182.dmg
SHA-256: 28dc21246a9c7cdedd2d6f0f4082e6bf7ef9db9ce9d485548e 8a9e1d19eae2ac

version 1.24
filename: KindleForPC-installer-1.24.51068.exe
SHA-256: c7a1a93763d102bca0fed9c16799789ae18c3322b1b3bdfbe8 c00422c32f83d7

version 1.26
filename: KindleForPC-installer-1.26.55076.exe
SHA-256: c9d104c4aad027a89ab92a521b7d64bdee422136cf562f8879 f0af96abd74511

filename: KindleForMac-55093.dmg
SHA-256: 580957ca56b1e77b7952f41970836481f37ada3071eaee3552 265069b89ef757

version 1.28
filename: KindleForPC-installer-1.28.57030.exe
SHA-256: 6feea6ec44ff3d3b7be23e7a969fe14ab884a7b19e23bc2c74 237730411559f6

filename: KindleForMac-57029.dmg
SHA-256: b4de86ba1b78966c754d220fe09fd7dbdbadd874b19e51d261 d8308e6e0d4cb3

version 1.34.1
filename: KindleForPC-installer-1.34.63103.exe
SHA-256: 3dc62b3895954fc171d4a3d08f2b7a1a503233e373c163adb7 bc7fd34cdeff49


**********************************************
Preventing undesired updates

The Kindle app can be aggressive about updating itself to the latest version. Even after the option to automatically install updates is deselected the software sometimes will update itself unexpectedly.

To block automatic updates under Windows locate the "updates" folder within your Kindle for PC installation and replace it with a file of the same name. The attached batch file ("disable k4pc download.bat") will perform that process automatically as long as Kindle for PC has been installed for single user use. After running this file Kindle for PC will still try to download the new update each time it is restarted, but it will be unable to do so.

See this post by odamizu for instructions to block automatic updates on the Mac platform.

When running the app if a dialog pops up indicating that a newer version is available always choose the option to "skip this version".

[bauerhjb]

to: jhowell

Thank you, thank you, thank you for this information. I was ready to give up on my free books from Amazon for the future since I got "improved" version of KindleforPC automatically today. Your directions for uninstalling and re-installing KindleforPC are excellent and worked great for me. One thing I'd like to add. I had downloaded my books once this morning right after the upgrade installed. Then when I tried to download them with the older version of KindleforPC. I found that I needed to go to Amazon and in manage my content, set the books up for delivery again. Once I did that, presto, chango everything was back to normal. Thanks again for the timely help. You are amazing.

[Rellwood]

I must be doing something wrong, because this problem hasn't effected me. All my AZW books are downloading as AZW3 and I have had no problems converting, transferring and reading. There must be some kind of catch here.

[Rellwood]

Nevermind. I still have 1.171

[Jo69]

Originally Posted by jhowell

Starting with version 1.19, Kindle for PC (and Kindle for Mac) often uses the new KFX format, which is incompatible with calibre.

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."

At the moment Kindle for PC version 1.17 is still available from Amazon and can be installed to work around this problem. I suggest following steps:

• Launch Kindle for PC 1.19 and under the menu choice "Tools", "Options", "General", uncheck "Automatically install updates when they are available without asking me."
• Exit Kindle for PC and uninstall it.
• Delete the contents of the "My Kindle Content" folder within your "Documents" folder.
• Download version 1.17 of Kindle for PC. It is safest to use the link in this post to download it directly from Amazon, instead of going to a third party site.
• Install the downloaded Kindle for PC version 1.17.
• Launch it and check that the option to automatically install updates is still turned off.
• If asked if you want to update to the new version always reject it.
• Re-download your books and import into calibre as before.

If you have an e-ink Kindle device registered to your Amazon account you have the option of downloading books directly from Amazon instead of using Kindle for PC.

• From the Amazon website access "Account & Lists" -> "Manage Your Content and Devices".
• Find a book you want to import into calibre and press the "..." button in the "Actions" column for that book.
• In the menu that pops up choose "Download & transfer via USB". Then select the name of your registered kindle device in the drop down menu and press the "Download" button.
• Import the downloaded file into calibre as you would a file from Kindle for PC. You will need to select the proper folder containing the downloaded file. (This folder will be different from the "My Kindle Content" folder used by Kindle for PC.)

Note: Users of the DRM Tools should refer to Apprentice Alf's Blog for information on the configuration required to support books downloaded for an e-ink Kindle.

This has worked well for me thanks

[Bookburner]

Thank you so much jhowell for those instructions on how to uninstall and roll back my kindle for pc to 1.17. I'm back in business.

[pdurrant]

I'm not sure if Kindle for Mac 1.19 does download as KFX. I just tried on a new user account, and all the books I tried came down in the old formats. (But inside folders in My Kindle Content)

Oh - but I didn't check for "Enhanced Typesetting" on the book pages at Amazon! Is it that only "Enhanced Typesetting" books comes down as KFX?

[tleon]

Thanks for this information.
For me only reverting to Kindle for PC version 1.17 did work. Downloading from the Amazon website does create AZW files but I was unable to import them into Calibre.

[jhowell]

(copied from another thread)

Check the Help/About menu to see what version of Kindle for PC you have. Anything before 1.19 doesn't support KFX. If you are using an older version then you probably have updates disabled since Amazon is aggressively pushing the new version to be automatically installed.

If you do have 1.19 or newer there are still some circumstances where books may be present in the older MOBI/KF8 formats supported by calibre.

Any books sent to the app before it was updated to 1.19 will still be in the older formats. You can identify these books because they will be .azw files in the My Kindle Content directory.

Books delivered after the app is updated to 1.19 are placed into subdirectories of My Kindle Content. Some of these will be in KFX format and some will be in the older formats. You can detect KFX because there will be a file with a name beginning with amzn1.drm-voucher.v1 in the same subdirectory.

There are several reasons that a book might still delivered to Kindle for PC 1.19 in an older format.

First, books that do not have Enhanced Typesetting listed on their product page are not delivered in KFX format. (There can be exceptions for fixed layout books.)

Second, it may be a book you purchased a while ago. Amazon locks you in to the version of the book that is current at the time you purchase it. If that version of the book did not support enhanced typesetting, but the product page for the book now shows that it does, you might or might not receive it in KFX format.

Also, KFX format is a moving target. New features are being continuously added to the format and some devices/apps do not support all of the optional features. If a book contains KFX features that a particular device/app does not support then MOBI/KF8 is delivered instead. I have found through testing that Kindle for PC 1.19 doesn't support all of the latest KFX features and so some books are excluded from being delivered in KFX to that app.

Finally, there may be other factors of which I am unaware.

[jhowell]

Originally Posted by pdurrant

I'm not sure if Kindle for Mac 1.19 does download as KFX. I just tried on a new user account, and all the books I tried came down in the old formats. (But inside folders in My Kindle Content)

Oh - but I didn't check for "Enhanced Typesetting" on the book pages at Amazon! Is it that only "Enhanced Typesetting" books comes down as KFX?

Perhaps Amazon is not (yet) delivering KFX to Kindle for Mac 1.19 for some reason. I do not have a Mac so I haven't tested it myself.

Looking at the installer for Kindle for Mac 1.19.1 it does have support for KFX in a file that appears to be installed to:
/Applications/Kindle.app/Contents/Frameworks/libKRFDynamic.dylib

See my previous post for some conditions under which KFX will not be delivered, including non-Enhanced Typesetting.

[DNSB]

Originally Posted by pdurrant

I'm not sure if Kindle for Mac 1.19 does download as KFX. I just tried on a new user account, and all the books I tried came down in the old formats. (But inside folders in My Kindle Content)

Oh - but I didn't check for "Enhanced Typesetting" on the book pages at Amazon! Is it that only "Enhanced Typesetting" books comes down as KFX?

I installed 1.19 for PC and 3 of my 5 test ebooks downloaded as KFX and did not import into Calibre.

I reverted to 1.17 and all 5 imported to Calibre.

[MRS_SOMERSET]

Hi,
I just wanted to say thank-you to the Calibre tech team for their post on how to deal with the new Kindle update ( that happened without my permission!)

I have been using Calibre for a while now to convert the books I buy to epub - why - because I have recently become partially sighted, (thats is a nats whisker away from being blind for those who do not know, and why should you ;-)

The reason being that I need a TTS ( text To Speech) software to be able to "read" my books, that is the software reads the text, rather robotically, but allows me to enjoy the books I buy, from Amaon for Kindle and other places, I have been an avid reader since I was 4, and have no intention of letting a mere issue of not being ble to see, get in the way of me accessing my books.

I started off with the super secret, not on the amazon website but official Amazon Kindle PC download for the blind which reads the text to you, as amazon and other publishers put their books in a format that TTS software cannot read - then that stopped working - on an update.

So I googled and chatted with other people with sight challenges and they recommended Calibre - and it was all working out fine until tonight when I bought, paid for and downloaded my new book from amazon, and when I opened up kindle it did an update, without asking, and when I went to convert the book it kept saying that it could not, so a quick search of the Calibre forum and a quick solution ( roll it back, find the hidden "automatically update without asking me button that is automatically set to on without the customer knowing" and turn it off.
and lo and behold I am able to convert the book and now able to have my TTS read it to me.

I know publishers like Amazon offer their own narrated versions of things, but having tried the free audible trial and finding that the narrator was so disinterested sounding, and got both the name of the main character and the title of the book wrong, repeatedly, I uninstalled that very quickly.

I am baffled, having worked with t he government many moons ago on ensuring accessibility in all electronic means, and the total faff it was back then to code, so much easier now to comply, why major companies make it so darn hard for us to get access to things ( I was not blind as a bat back then, it was just part of my job - who knew, an untreated autoimmune disease and bobs your uncle and I am rather stuffed)

So, after all that waffle, I just wanted to say that I am ever so grateful to companies like Calibre who make life easier for us with disabilities, and not only that - keep on top of things and continue to offer advice and support, especially when those who should know better get up to nefarious activities.

[kovidgoyal]

You're welcome

[pmjeff21]

I just followed these steps of removing the newer Kindle for PC app, installing the old, etc. My "classics" which are public domain convert from AWZ to EPUB just fine, but books I bought recently (Tim Ferriss, Tools of Titans, for example) give me the DRM error in Calibre.

I don't have any branded devices, just a Windows 10 Phone (Lumia 930) and a Surface Pro 4. Amazon killed off their app, so now I'm stuck with unreadable books except for the clunky PC version of Kindle.

Any ideas of what I'm doing wrong? I'm brand new to Calibre and this whole EPUB & DRM thing.

[jhowell]

If you followed the steps in the first post and are getting DRM errors then I suggest that you check out Apprentice Alf's Blog for further assistance with that.