Difference Between Kindle Content AZW, AZW3, PRC, Mobi, Topaz, AZW6, KFX

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Amazon Kindle has the largest eBooks capacity in the world, and (maybe) the most complicated eBooks format mechanism. In the most of other eBook stores, we usually get only two formats: EPUB and PDF. While in Amazon Kindle, we can see AZW, AZW3, PRC, Mobi, HTMLZ, and more...

Although a Kindle book can be delivered as any of these formats and almost looks the same. In fact there is difference between them, it might be tiny, but you shall not ignore it.

Following are detailed introduction and explaination.

different kindles

What is AZW

AZW is the most popular format for Amazon Kindle books, it might stand for Amazon Word, but Amazon hasn't officially confirm that yet.

If we sync the purchased Kindle books to local computer via Kindle for PC/Mac, the synced books are usually saved in .azw format and protected by Kindle DRM.

If an AZW file's DRM protection is eliminated, it can be directly renamed to Mobi while keeping the file complete and read by the reader software like Kindle for PC or MobiPocket Reader.

To remove DRM from AZW is pretty simple, just make sure the files are synced via Kindle for PC/Mac, then use Kindle DRM Removal to handle them, no extra job is required.

Here is a brief guide: Remove DRM from Amazon Kindle AZW files

What is AZW3 (KF8)

AZW3 is a variation of AZW and also known as KF8. At the beginning it was only supported by Kindle Fire tablet, and later expanded to forth generation of Kindle, and Kindle for PC/Mac.

Compared to AZW or Mobi, it is more advanced by supporting more styles, fonts and layout. And I can see the trends that AZW3 is gradually replacing Mobi.

At the moment, books directly downloaded to recent generations E-Ink Kindle are uaually delivered as AZW3 format and protected by DRM. While some AZW files synced by Kindle for PC/Mac would also turn to AZW3 after the DRM protection is removed.

If you want to strip the DRM from AZW3 files downloaded on E-Ink Kindle, please read: How to Remove DRM From AZW3 eBook Files

PRC and Mobi

When a PRC file and a Mobi file are all DRM-free, then we can simply say they are exactly the same thing. But when they are protected by DRM, things are going differently.

If a purchased Kindle book is downloaded to Android device, in other words, synced by Kindle for Android app, then the format would be PRC. And we shall note that Kindle Fire tablets are also Android devices in actual, so the books directly downloaded to Kindle Fire tablets would also save as PRC format.

Read this post you can know how to remove Kindle DRM with Android devices: PRC DRM Removal for Kindle Android Books

And the most of Mobi books are DRM-free nowadays, as Amazon transform them to AZW once they are protected by DRM.

Topaz (TPZ, or AZW1)

Generally speaking, all the formats above are basically generated upon Mobi and AZW, but the Topaz, or the variations TPZ and AZW1, are pretty different. And the difference mainly manifest in the file structure and data base, that's not what we are discussing here.

The Topaz files are always DRM-free, when thy are protected by Kindle, they change to TPZ or AZW1.

If a Topaz book synced via Kindle's Whispersync, it becomes AZW1; if directly downloaded from the website, it becomes TPZ.

Remove DRM from TPZ/AZW1 books are the same as from AZW, so you can also read this guide: Remove DRM from Amazon Kindle TPZ, AZW1, Topaz files

And the HTMLZ? It is just a zip archive of HTML files.


AZW6 files are very rare, they mainly appear in Japan Kindle store's manga books.

AZW6 file only contains texts, all the images in the book are saved in the related folder. So if you convert an AZW6 book to another format, all the images will be gone, as they are not contained in the book.

But why? All AZW6 books I got contain lots of images, Amazon make it work like this for better reading experience.

Imagine you buy a Kindke AZW6 book (you don't know its format before buying) in a place with poor WiFi network, then this book will download low quality images, you needn't wait a long time to start reading the book. When you go to a place with strong WiFi, Kindle will download high quality images to replace those low quality images automatically.


KFX is the latest format of Amazon Kindle, to get this format of file you must have an E-Ink Kindle, and the book should have the "Enhanced Typesettings" property (you can find this property in Amazon product page).

KFX is the successor of AZW6, it's even not a real eBook file. You can see it as a downloader, it downloads all the stuff of a book into your Kindle, no matter texts or images.

So there is no change at all to convert a KFX file to another format or decrypt a KFX file.

However, you have alternative solution to convert KFX to Mobi/EPUB/PDF.

Infographic about these defferences

difference between kindle content infographic



joined Epubor since 2011, loves everything about eBooks and eReaders. He seeks the methods to read eBooks more freely and wants to share all he has got with you.

01/21/2014 14:49:16
Thank you for that. I was having trouble with which was which. Trying to format and certain files did not indent a block quote on both sides. Mobi did not so I tried the AZW3 you mention, and it does it.
05/20/2014 14:12:29
It figures that there has to be one company that makes things difficult. I'm an independent author who only wants it to be simple. Now I have to wonder if the mobi files I upload will work for my readers.
07/2/2014 05:39:17
Why won't my prc files show on my kindle fire but do on my dimple kindle.thanks
07/9/2014 23:56:40

To transfer ebook files to Kindle tablet/ereader, I would recommend you use "Transfer to Kindle" service.

Here is the guide post: www.epubor.com/transfer-books-to-kindle-kindle-fire-hd-paperwhite-kindle-for-androidipad-app-from-pcmac.html

10/8/2015 02:00:22

Hi. Thanks for this!

I was wondering if there is any Kindle format that supports embedded audio and video across all devices such as iOS, Android, PC and Mac.

Will appreciate some advice.


10/22/2015 15:41:01
Thanks for this post. It's exactly what I wanted to know. I'm converting epub for my PaperWhite and was wondering about .mobi vs. .azw3.
10/22/2015 15:41:03
For decrypting books from Kindle device:
1, Connect Kindle to computer with USB cable.
2, Directly drag the books from rightside column into leftside main window.

For decrypting books from Kindle for PC/Mac:
1, Download and authorize Kindle for PC/Mac with your Amazon ID.
2, Launch Kindle for PC/Mac, sync all books to your computer and make sure you can read all the books.
3, Run Epubor software, all done.

Detailed info: http://www.epubor.com/faq.html

06/28/2016 19:47:33

Now the newest version of Epubor Ultimate supports output both "Mobi" and "AZW3".

You can try to convert your EPUB to these 2 formats, then choose a better one you like.

11/10/2015 07:58:30
Who leaves the typo with the red squiggly underline on a published infographic? So unprofessional.
07/27/2016 12:03:54
Bitchy a little?
12/1/2015 15:12:10
I'm having some trouble when I send non-amazon purchased books to the kindle app on my iPad Mini 3. Sometimes, the cover of the book is stripped and replaced with a generic word template with the title of the book. I've been trying to figure out why it only happens sometimes and I'm leaning towards thinking that only books with the AZW extension come through to the kindle app fine. I've sent books with the Mobi and PRC extensions and they are stripped of their covers while books with the AZW3 don't get uploaded at all. Is there a converter out there that will convert from Mobi to AZW because all the converters I've found change to the AZW3 extension? Any help you can provide would be greatly appreciated. Thanks!!
06/28/2016 19:43:37


No, now all the converters only supports Kindle's AZW3 or Mobi output.

I recommend you make sure you're using Epubor Ultimate(newest version), which may solved your problems that cover stripped.

And you can also add covers to your books by metadata editing.

02/5/2016 19:53:03
I have an older kindle and have been converting my epub to azw but the new converter i bought only does azw3 and does not show on my older kindle. Is there a free coverter that will convert azw3 to azw?
06/28/2016 19:37:01


If you want to convert your EPUB book to Kindle and show on your old Kindle device, I recommend you use Epubor software or our free online service to convert the EPUB to Mobi(native Kindle format).


12/13/2016 03:23:33

Jonny - YOU ROCK!

Very informative, helpful and extremely well-written article.
Thank you for taking the time to write it and for sharing your knowledge.
Greatly appreciated.

01/14/2017 02:05:56

I purchased a textbook from amazon.
I want to remove DRM so that I could sync it to iBooks (I don't like kindle reader), and also so that one day Amazon doesn't just decide to pull it off if the lose a contract with the publisher (like that 1984 conundrum).

So, I opened the folder where my content is stored and it has several files:

.azw4  -- 190 MB
.azw   -- 27  MB
.mbp   -- 120 bytes
.phl   -- 1   kb
.mbpV2 -- 242 bytes

I assume my main guy is .azw4 since it's the largest file, but what's that also pretty large 27MB .azw file for?
And what's the purpose of the rest of the files (smaller ones)?

Should I be able to convert it to a DRM-free pdf file?

Thank you.

01/14/2017 02:05:58
For decrypting books from Kindle device:
1, Connect Kindle to computer with USB cable.
2, Directly drag the books from rightside column into leftside main window.

For decrypting books from Kindle for PC/Mac:
1, Download and authorize Kindle for PC/Mac with your Amazon ID.
2, Launch Kindle for PC/Mac, sync all books to your computer and make sure you can read all the books.
3, Run Epubor software, all done.

Detailed info: http://www.epubor.com/faq.html

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Home > Guide >Difference Between Kindle Content AZW, AZW3, PRC, Mobi, Topaz
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