How to Convert KFX Books to EPUB/AZW3/Mobi/PDF

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In recent months, owing to the update of Kindle system, many new downloaded Kindle ebooks are KFX format. It's a new format of Amazon Kindle ebooks, which is not very familiar to us. Now it's not only supported on the latest Kindle eReader and Kindle iOS app, but also Kindle for PC version 1.19. To read Kindle KFX files on more reading apps or devices, we need to convert KFX format to other widely used formats like ePub and PDF format.

In this article, I am going to tell you how to converter KFX books to EPUB/AZW3/Mobi/PDF formats:

What's the KFX file and when will we get it

In August 2015, all the Kindle eReaders rolled out within the last 2 years were updated with a new typesetting and layout engine that adds hyphens, improved word spacing and ligatures to the eBooks that support this engine require the use of the new KFX format of Amazon.

I guess most of people are not familiar with the new KFX format. But do you know when and how will we get this new KFX file? In fact, not all the books we downloaded are with KFX extension. At the very beginning, if we use the latest Kindle eReader such as Kindle Paperwhite or Kindle Voyage and download eBooks supported enhanced typesetting, we will get KFX file. However, Amazon Kindle upgrade its Kindle for PC to version 1.19 on 18 Jan 2017 which also supports the KFX format.

Skip to how to convert KFX file to EPUB/AZW3/Mobi/PDF from Kindle for PC/Mac.

But it’s not quite easy yet to get KFX books. Not all Kindle books support the new layout engine. Amazon has claimed that there are around 100,000 eBooks on their website which are in the new KFX format. If you want to find whether the book supports new KFX format, just look on the book's description page on Amazon. You can see a label that shows if enhanced typesetting has been enabled.

kindle books with enhanced typesettings

If we have got KFX file, when we connect our Kindle to computer via USB, we can find KFX file in Kindle "document" folder are with .kfx extension.

kfx files on kindle device

How to convert KFX books to EPUB/AZW3/Mobi/PDF

As the KFX is the new format of Amazon, currently, there is no eBook Converter including Calibre can directly convert this file to other common formats (update 2018 April: we can use Calibre plugin to convert KFX books now). If we add or drag a KFX file to Calibre or other eBook Converters, it usually shows up an alert "unknown eBook type or unsupported eBook format". Does this imply that we cannot convert KFX books to other formats we like? Of course not, though we cannot directly convert KFX books to EPUB/AZW3/Mobi/PDF format, there are another 2 indirect methods for us to handle KFX file.

We can sync our downloaded KFX files on our Kindle via Kindle for PC/Mac(version 1.17), and we will get the common used AZW format. Or We can directly download KFX file which has already synced via our Kindle from Amazon website, then it will be saved as AZW3 or AZW file on our computer, just transfer it to Kindle via USB. If we have got common AZW or AZW3 files, then we can use a professional eBook Converter to convert KFX to EPUB/AZW3/PDF/Mobi format. Next I will introduce you 2 methods in details. But before that, we have to prepare the tool first.

First at first, get the tool ready

Epubor Ultimate is the first software that can strip KFX DRM directly and losslessly. It can convert both DRM free and DRM protected KFX books to EPUB/AZW3/Mobi/PDF. It also supports batch conversion. We can convert more than 1 file at a time within seconds. Besides this, you can try the 30-days free trial .

Download the tool for free

Old solution 1: Degrade Kindle for PC/Mac to version 1.17

Step1: Downgrade the Kindle for PC/Mac to version 1.17

Since the updated Kindle for PC/Mac version 1.19 supports KFX format, if you sync your downloaded KFX file on your kindle via Kindle for PC/Mac version 1.19, you will get KFX file but not the AZW book as via Kindle for PC/Mac version 1.17.

To convert the KFX books, you have to downgrade your Kindle for PC/MAC to version 1.17 or older version.

Kindle for PC V1.17 Download Kindle for Mac V1.17 Download


After the installation, you have to turn off the automatic update function for Kindle for PC/Mac. Open the Kindle for PC/Mac, choose"Tools" and select " options" at its drop down list, you will find the general options. Then un-check"Autommatically install updates when they are available withou asking me." and click save.

uncheck kindle update

Step2: Sync KFX books via Kindle for PC/Mac(Version 1.17)

Log in your Kindle for PC/Mac, click the "Archived Items" on the left side and find the KFX books you have downloaded on your Kindle device, then double-click its cover to download it to your computer.

downlaod kfx file via kindle for pc

After the download has been finished, you will find they are saved as common AZW format, instead of the KFX file.

sync kindle books via kindle for pc

Step3: Remove DRM from Kindle books AZW

As most of downloaded Kindle books are protected by Kindle DRM, we'd better remove DRM first in order to convert eBook format.

Run Ultimate eBook Converter, usually if your downloaded books are saved in the default folder "My Kindle Content", they will be automatically detected and uploaded to this software. You can see them under "Kindle" icon. A really friendly design for users. No need to add books manually.

Next, what we need to do is to drag Kindle books from the left side to the right frame of this program. Then all the added books will be decrypted soon. You can see the word "decrypted", which shows books have been removed DRM successfully.

remove drm from kindle books

Step4: Convert KFX to EPUB/PDF/Mobi/AZW3

After we have removed Kindle DRM successfully, now we can convert DRM free books to EPUB/PDF/Mobi/AZW3. As the image above shows, after removing DRM from AZW file, the decrypted books are Mobi or AZW3 format. So we don't need to convert all of them to Mobi or AZW3 files anymore.

To convert decrypted Kindle files to EPUB/PDF, just choose "EPUB" or PDF as the output format, then click "Convert" button to start conversion.

convert kfx file to epub/pdf

When the conversion has been finished, you will see a "Succeeded" on the right side of your added books, at the same time, a window will pop up, which shows us all the converted files.

convert kfx to epub pdf mobi successfully

Old solution 2: Convert KFX files directly downloaded from Amazon website

Besides method 1, there is another useful way to convert KFX books to EPUB/AZW3/Mobi/PDF.

Step1: Download purchased books from Amazon website

Enter Amazon website, log in it with your Amazon account. Then hover over the "Your Account" drop-down menu, select "Manage Your Content and Devices", you can see all your Kindle content here. Just find the KFX books you have downloaded via Kindle device, then tap the button under "Actions", click "Download & transfer via USB".

download kfx books from amazon website

Then a following window will pop up, just select the Kindle to which you want to transfer the book. Then click "Download" button to download the book to your computer.

download KFX file from amazon website

You can see these downloaded files will be saved as AZW or AZW3 files, while we will get KFX file if we sync them via Kindle device.

downloaded kfx file saved as azw azw3

After downloading, what we need to do is only to connect our computer to Kindle via USB and transfer downloaded books from computer to Kindle's document folder.

Note: Downloaded AZW or AZW3 files can only be opened on the Kindle you have selected and are always protected by Kindle DRM, you cannot open them via Kindle for PC/Mac or other Kindle devices.

Step2: Remove Kindle DRM from Kindle e-Ink device

If we want to convert KFX to EPUB/PDF, we also need to remove Kindle DRM from Kindle e-Ink device. It's easier. Just connect Kindle to computer, drag books from the left side to the right panel. Then all the downloaded books will be decrypted.

remove kindle drm from Kindle e-ink device

Step3: Convert KFX to EPUB/PDF/Mobi/AZW3

This step is the same as step4 mentioned in the method1. So here I won't introduce it again.

Newest solution: Remove KFX DRM 2017 directly and convert formats

Updated 12/21/2018: This method does not apply to Kindle KFX eBooks downloaded via Kindle for PC/Mac version 1.25 and Kindle eInk device with firmware 5.10.2.

Good news that you must know is that, since 19th, October 2017, we have upgraded our software to remove DRM from Kindle KFX directly so you do not have to degrade your Kindle for PC/MAC to older version. What's more, you can even strip DRM from the Kindle KFX eBooks downloaded via Kindle devices.

Please install the latest version of Epubor Ultimate.

Download the Epubor Ultimate for free:

When you open Epubor Ultimate, please click on "Kindle" tab at the left column of interface. All downloaded Kindle books will be sideloaded. To remove the Kindle DRM, you just have to drag and drop the Kindle books from the left to the right. You will see "Decrypted" at the end of each book title. Now you get the decrypted Kindle KFX eBooks.

Please keep in mind that, if your books are synced via Kindle desktop ( no matter which version it is), those eBooks' extension will be .azw, even though there are truely the KFX format. But don't worry epubor ultimate will be your liberator.

convert KFX ebooks

Note: Epubor Ultimate also can convert Kindle KFX ebooks downloaded via Kindle e-ink device.

Another advantage of using epubor ultimate newest version is that, if your Kindle KFX books are downloaded from Kindle e-ink devices such as Kindle Paperwhite 3, it will also detect those books automatically and decrypt them.

convert KFX ebooks 2017

See? All KFX books are decrypted quickly with this tool. You can also read this article how to remove DRM from Kindle books 2017 to learn more information.

If you have all your books decrypted, just choose the output format for your books. Then click on"Convert to Epub". All Kindle kfx books will be converted to EPUB.

remove Kindle KFX DRM

As we can see the picture above, all Kindle Books have been converted successfully.

Note: In general, decrypted Kindle books can be read directly on kindle devices, apps or another third-party reading apps, such as Calibre. But the drm removed KFX books will be still kfx format (drm free), they can be read on Kindle reader app or device, but can't be directly read via other third-party app, such as, Calibre.

kfx zip

As the image shows, Calibre treat the drm free kfx book as KFX-ZIP, but can't help you view it in its built-in reader. So in this situation you must convert drm free KFX books to Mobi or AZW3 format.

What a friendly and powerful software! Almost all the operation is automatic, we can convert KFX files to EPUB/PDF/Mobi with only 2 clicks. What's more, its conversion speed is super fast, which can really save us a lot of time.

If you are wondering how to convert KFX file to EPUB/PDF/Mobi, why not try this useful software which offers 30-free trial to help you decrpt your KFX file and convert format?

Start my free trial

Make your KFX files freely and readable on any portable devices


works for Epubor and writes articles for a collection of blogs such as ebookconverter.blogspot.com.

01/31/2017 23:50:10

January 31, 2017  Tried the trial version of your software.

Since January 19, 2017, all but a few of the Kindle books from Amazon have the new KFX format.   I use Kindle for PC latest version which downloads the books with a .AZW file extension. If you look at the first few bytes of the KFX book files with a hex editor, you will see:  xDRMIONxxx.

Calibre has been updated to handle an unencrypted KFX file but the Apprentice Alf decrypter addon does not work yet.  Apprentice Alf gives identical error messages to your software so I suppose you are using the same open source decrypting code.

I will check back periodically for an update but as of this time I cannot use your product and have uninstalled it.  When there is an update available I will reinstall it and hope that a new 30 day trial is available.

02/6/2017 11:19:36
If you download the book using an old version (say 16 or 17) of the Amazon Kindle for PC then you get an AZW version that you can use.
02/10/2017 11:16:17
Because Kindle for PC/Mac has automatically upgrade to v1.19, that makes kindle books are changed to KFX file format.
Please downgrade to v1.17 or older version.
Kindle for PC v1.17 download here:
Kindle for Mac v1.17 download here:
After downgrade to Kindle for PC/Mac, please delete and sync all books to your computer again, then run Epubor software.
Note: Kindle for PC/Mac --> tools --> options --> General, then un-check "Automatically install updates".
03/8/2017 05:54:38

Hey Bob,

I was having similar issues to what you are experiencing.

I purchased an ebook via amazon but don't own a kindle and wanted to have it in pdf format. Since the kindle app is horrific and barely usable.

But I finally got around it by:

1) Navigated to the "My Kindle Content" folder and deleted all the files there.

-Keep in mind that I just had one amazon ebook in my kindle for PC library.

2) Downgrading Kindle for PC from the latest version to version Kindle for PC v1.17

-I actually downloaded it from else where cause I was a bit sceptical, though the file made available by these awesome fellows is fine.

3) Re-downloaded the ebook through the downgraded kindle for PC v1.17

4) I then opened the Ultimate converter app and just followed the instructions above..it immediately recognised and converted the book to pdf.

02/23/2017 01:37:59
This is all very well but very soon (I fear) Amazon will force an upgrade to v 1.19 and will no longer support early versions (as they did in the past) When that happens, you will no longer be able to sync your library unless you upgrade and then will end up with kfx books which the current decryption solution cannot handle (Epubor or Apprentice Alf DeDRM) calibre plugin)  Is the party over?
09/8/2018 11:41:36
Epubor will keep updating the software to remove the latest version of Amazon DRM. And the fact proves that we are the first and best eBook DRM removal developer.
04/15/2017 23:43:32

Dear epubor,

Will there be an update soon (or eventually) to epubor ultimate so that we don't have to go through these additional steps? I purchased this program to be able to convert and remove DRM almost with one click, not to have to go through this additional process.

If an update to take care of this is not in the works, I suggest that you make it clear that the program will not work with the newer KFX Kindle format so that buyers aren't misled into thinking that this will work for them as advertised and that there are additional steps they will need to go through.

I am a satisfied user of epubor ultimate so far but I do hope that an update will be made ready soon. I'm not angry about this as these things happen, but I believe that you should be working on a solution to this that doesn't require the additional steps.

Thanks so far for making a great product.

lifetime licensed user

04/26/2017 10:21:22
Thanks for your advice. We are always trying to update our software to omit these steps. But it takes time. Once we have made progress, we will inform our consumers. Best regards!
06/1/2017 10:46:03

To transfer Non-Amazon books to Kindle Android apps, please convert the books to Mobi format at first.
Then please follow the following steps:
1. Connect your Android tablet,
2, Go to the "Kindle" folder of your Android device storage. Copy and paste the MOBI books to that folder,
3, Tap the menu icon in the top right corner of Kindle app, then select "On Device" to check the transferred books.

01/8/2018 05:42:46
What about free trial? I want to try before to purcase...
01/10/2018 09:58:41
For the free trial, you just have to download it and try it! It will work smoothly. But the trial version only can convert 20% content of each book~
03/28/2018 15:44:08
WIll it be possible to convert KFX directly to epub or mobi in few years ?
03/31/2018 14:11:38
Epubor Ultimate can convert Kindle KFX to epub and mobi directly now. You are welcome to download our trial version to have a free trial.
09/8/2018 11:40:02
Successful! Thanks!
06/18/2019 10:13:08
So i downloaded and installed the kindle from the link provided and amazon asked me to verify my account using an OTP. Surprisingly the OTP was sent by my bank. So not sure what exactly happened.
06/18/2019 10:34:40
Thank you for your comments. For the one time passwords, it never should be related to your bank account but your amazon registered email. Please check this email to get the one time passwords.
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