I see one other question here regarding this topic, but no answer is accepted, and nor do any of the files/file formats mentioned in those answers match the filetypes I see.

I work on two monitors and when using docs, like to have the doc open in a decent PDF reader - much better UX than the simple Windows 10 Kindle App, which I don't like very much.

When I connect my Kindle to the PC, and open its documents folder, I find my book in a folder with its title as name and .sdr as its extension. This folder contains 3 .asc files, and one .azw3f and one .azw3r file.

None of these files are large enough for a book, but it does show under "Downloaded" when I check it on my kindle.

Is there any way I can go about using these files to covert the book to PDF, or is there a special converter I can just pass the whole .sdr folder to and have it do all the conversion "paperword"?

  • Did you do any research before asking this question? – DavidPostill Nov 11 '17 at 18:25
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  • @DavidPostill I did do research, and all I found were resources dealing with converting a single file on the Kindke. I quote "Afterward, locate the Kindle file you wish to convert — most likely formatted in Amazon’s proprietary file type, AZW or MOBI". I don't find any such files in my kindle book folders, so I asked this question and included details of the file types in the folder for the book to convert, and there are only i kB .azw3f and .azw3r files, no plain AZW or MOBI files. – ProfK Nov 11 '17 at 22:59
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    Chances are you will need to "root" your kindle to find your actual book files which are likely to be stored in the kindle app data directory rather than a user accessible data area. – Mokubai Nov 14 '17 at 7:59
  • could you please provide a full directory/file list you can see in your device? It may help us identify the new kindle structure, as the old one was pretty straight-forward, I cant imagine where your problem is, and i'm neither updating my kindle to find out I got screwed :p. Anyway, bulk-converting may be a pain, specially if you want to get perfect formatting, so often you need to add your own conversion rules to Calibre, or modify the original books "by hand" a bit before the conversion. I dunno if there's commercial software that solves this, but with freeware its usually the way to go. – DGoiko Nov 17 '17 at 18:43

The .sdr file is the "sidecard" folder which contains files that have additional information:

An .azw3f file contains metadata (e.g. author, number of pages) for a corresponding .azw file.

The .azw3r file also contains additional information, but I don't know details.

In other words, these files are not your book. So there's no way to convert those files to a PDF.

Your book is likely an .azw file, and stored in a different folder, and you can use your research results to convert it to a PDF file once you've found it.


Your problem is that Kindle moved to a new format that cannot be easily converted.

The solution is pretty easy : Uninstall your too-new Kindle version, and install Kindle for PC 1.17.0, then re-acquire your books which will this time be in a format that is easier to convert.

An excellent converting tool is the free calibre. You may also need this add-on.


This is a pretty thorough question. First of all, Kindle file structure has evolved over time, so if we don't know your software and kindle's version it's quite hard to give you a more precise answer.

There are some things you could try, though:

  • Install Calibre and check if it allows you to import the book from the Kindle to your computer, in which case you'll have the files available directly in your hard drive, inside the library folder.
  • Use Kindle Collection Manager to browse through your books, but it's pretty old, I don't know if it will work on modern devices.
  • Downgrade your Kindle software, as someone said in another answer.
  • Here you have a list of different ways to load books on your kindle, probably one of those will allow you to extract the book itself. It basically states calibre, cloud, web browser, Kindle apps, email, USB.
  • If you use Kindle Fire, check this link: They explain how to install a file browser on the kindle. It shows you how to install ES File Explorer in order to browse your Kindle's storage.

I'm almost sure using Calibre to import your books onto your hard drive is the way to start.

Kindle supported formats are described here, it may give you a deeper insight into how is your book exactly stored on the disk.

About the PDF conversion, I've always used Calibre, but mostly in the other way: PDF->kindle format, however, sometimes you have to tune the parameters by hand to obtain an acceptable conversion. This is calibre's conversion manual, however, depending on your data sources, you may need a bit more advanced guide to convert properly.

Please, provide more detailed info, like Kindle hardware and software version and what software (and version) you are using to access your device.

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