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How Do I Read Library Books on My Kindle? Part 2: ePub

Last month I figured out how to put Mobipocket format books on the Kindle. Unfortunately, that leaves out the vast majority of library books out there, which are in ePub format. I put off figuring out ePub this long because I thought it was going to be much more complicated, but it’s actually not. However, most ePub books are Adobe ePub, and therefore DRM-protected, so we’re wading into an ethical gray area. But let’s deal with the unprotected kind first.

Unprotected ePubs

These are available, for example, at Google Books and Project Gutenberg. All you have to do is change the format to one that can be read on the Kindle: specifically, Mobipocket.

The first time:

  • Download the Calibre program. Move it to Applications.
  • Open it and run the welcome wizard (under the Tools icon in the top right corner, if it doesn’t start automatically).

Each time you download a book:

  • Click the Add Book icon in the upper left corner and choose the book you downloaded.
  • Highlight the new book and click the Convert Book icon at the top.
  • Once it’s done converting, and your Kindle is plugged in to the computer, click the Send to Device icon at the top. I said it was easy, didn’t I?

DRM-Protected ePubs

In order to convert an Adobe ePub book with DRM to a format readable by the Kindle, the DRM has to be completely stripped. This removes the software that makes a library book expire after its due date, so it’s technically illegal. Personally, I would feel comfortable doing this because it’s a library book, not something stolen, and I’d be reading it once, not putting it online or trying to sell it. But you make your own call.

The first time:

  • Install Digital Editions.
  • Go to this blog and download both the key-retrieval script and the decryption script.
  • Double click “”
  • This will bring up an IDLE window. In the menu, click Run, then Run Module.
  • You should get a pop-up window that says “Key successfully retrieved to adeptkey.der.” Keep this file. You’ll need that key to convert each book.

Each time you download a book:

  • Double click the book file. This opens it in Digital Editions and converts it from .acsm to .epub.
  • Double click “”
  • This will bring up an IDLE window. In the menu, click Run, then Run Module.
  • You should get a pop-up window that says “Select files for decryption”. Choose the file you want to decrypt. It’s usually in Documents, Digital Editions.
  • This should output an unprotected .epub file. Follow the steps above to convert it.

I think this may be even easier than making Mobipocket books readable on the Kindle, mostly because the Calibre program is awesome. But even after doing all this research, I don’t think I’m going to be using this information very often—it’s just so much easier finding books on Amazon than trolling through library sites.

Didn’t answer your question? Check out part 3, Calibre Plugins.

One year ago: Worm Composting.


Comment from Sharon
Time July 23, 2010 at 8:08 am

But dude, they cost MONEY!

Comment from Linds
Time July 27, 2010 at 1:14 pm

I think I love you for this information — but I might need your help if I try this….

Comment from Brenda Pike
Time July 27, 2010 at 1:23 pm

But your method takes so much TIME!

Comment from Brenda Pike
Time July 27, 2010 at 1:24 pm

I (or Jason) can definitely help you. And let me know if any of the instructions are unclear, too, so I can update the post.

Pingback from Pragmatic Environmentalism
Time July 31, 2010 at 12:02 pm

[…] DRM if you’re not doing so to infringe copyright – Boing Boing. On the heels of my ePub post, this is a relief. (Thanks, […]

Comment from friendofthepeople
Time August 9, 2010 at 3:01 pm

Thanks a lot for this. This is especially useful how Apple’s limited all use of DRM protected books. Worked perfectly, and my PC is still in tact. 🙂

Pingback from Pragmatic Environmentalism
Time September 7, 2010 at 9:45 pm

[…] Didn’t answer your question? Check out part 2, ePub. […]

Comment from Rebecca
Time January 15, 2011 at 1:14 pm

Thanks for this!!! This was super helpful. 🙂

Comment from melissa
Time March 7, 2011 at 11:08 am

Where should I save the .py files? Also my computer is saying it doesn’t have a program to open them?

Comment from Brenda Pike
Time March 7, 2011 at 9:25 pm

My tech guru says:

She’s obviously running on a PC. Since that’s the case, she needs to do one additional step: Install Python version 2.6, which is available here. Just click on the Windows x86 MSI installer to download it and follow the install instructions.

It doesn’t matter where she puts them. Just stick ’em in a folder where she’ll remember where they are.

Comment from Jen
Time March 31, 2011 at 6:04 pm

Help! Just trying to get a readable epub ebook for my Kindle. I have followed the instructions as far as getting a box that says adeptkey.der found etc but I cannot open the file that is then saved. It says I need a security certificate? Also, am I missing something between opening my book file in Digital Editions and double clicking as nothing by that name can be found on my computer. It’s running windows vista btw.

Thanks for this article – I haven’t got a clue about this kind of thing and this guide has really helped me so far!

Comment from Jason
Time April 2, 2011 at 10:16 pm

My advice would be to move all of the files that you want to decrypt into the same folder: the .py files ( and, the adeptkey.der, and the epub . Then run the ineptpub script.

There shouldn’t really be a need to open the adeptkey.der file; it just needs to exist in the same place as the file so the script can use it to do the decryption.

Comment from David
Time May 1, 2011 at 9:48 pm

Thanks for this, it’s awesome but…I’m running Mac. Everything works perfectly until I need to select my file for decryption. The acsm file is faded ie. I’m not able to select it as a file to decrypt. What am I missing. Thanks.

Comment from Jason Braley
Time May 7, 2011 at 9:26 am


The acsm file isn’t actually an ebook; it’s more like a link on a web page. What you need to do is double-click on the acsm file, which should open up Adobe Digital Editions and start the download of the actual file you’ll need to decrypt. That file will be located in the Documents/Digital Editions folder with the file extension .epub. Now, run the decryption on the epub file. Hope that helps.

Comment from Becca
Time June 20, 2011 at 6:10 am

I am having trouble in the last step. I am getting an error message (Error: File is not a zip file.)

Also, in the “My Digital Editions” folder contains my book in an Adobe Acrobat format, rather than an .epub file format.

Does anyone have any tips for me? I just want to read my library book on my Kindle! Thanks!

Comment from Emily
Time July 28, 2011 at 6:07 pm

i am new to all of this and I can’t seem to get the file to run. Everytime i click run then run module it says syntax error.. Can someone please help? Also, I am trying to do this on a macbook pro

Thank you!

Comment from Marisa
Time October 10, 2011 at 12:57 pm

Emily, this is probably way too late to help you, but in case anyone else is having the same problem: you have to use Python 2.7 (or earlier, I suppose) to run the file. Python 3.x isn’t back-compatible with older scripts, and this script was written prior to python 3.0. (Some details here:

Comment from Rob
Time October 28, 2011 at 3:39 am

Thanks so much for that. Took my time and persisted and everything works great. I’m a happy man.

Comment from Liesel van Eeden
Time February 11, 2012 at 5:22 am

Can you please help? I get an error when running the ineptkey – Error:Failed to decrypt user key key (sic).

Comment from martin
Time August 16, 2012 at 8:41 pm

Like Becca I get a pdf file and not an epub …. how does one solve this?

Comment from Brenda Pike
Time August 16, 2012 at 8:45 pm

Try downloading the new plugins. That way you don’t have to mess around with Python.

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