Frequently Asked Questions about the DRM removal tools

Apprentice Harper keeps a more up-to-date FAQs at the GitHub repository:

Post updated on 12 January, 2017

Where can I find out more about ebook Formats and DRM Removal Tools?

  • This post explains the various ebook formats and DRM schemes. A guide for the perplexed.
  • This post describes how to install and use the DeDRM plugin for calibre.
  • This post gives the information you need to use the Windows DeDRM application which doesn’t need calibre.
  • This post gives the same information for the Mac OS X DeDRM application.
  • This post has links to downloading a zip archive of all the tools, as well as a comments area for asking questions.

Getting and Using the Tools

I can’t get the tools to work on my rented or library ebooks.

Support for removing DRM from rented or library ebooks is not provided.

I am trying to install the calibre plugin, but calibre keeps on saying that the plugin is invalid.

You might be trying to add the tools archive. The tools archive is not a calibre plugin. It is a collection of various DRM removal tools which includes calibre plugin. You must unzip the archive, and install the calibre plugin from a folder called “DeDRM_calibre_plugin” in the unzipped archive.

I’ve fully unzipped the tools archive, but I can’t find the calibre plugin when I try to add them to calibre. I use Windows.

You should select the zip file that is in the “DeDRM_calibre_plugin” folder, not any files inside the plugin’s zip archive. Make sure you are selecting from the tools folder that you created when you right clicked and selected “Extract All…” on the tools zip archive and not selecting a file inside the still-zipped tools archive.

(The problem is that Windows will allow apps to browse inside zip archives without needing to unzip them first. If there are zip archives inside the main zip archives, Windows will show them as unzipped as well. So what happens is people will unzip the to create the DeDRM_tools_X.X.X folder but when using calibre they will actually navigate to the still zipped file by mistake and cannot tell they have done so because they do not have file extensions showing. So to the unwary Windows user, it appears that the zip archive was unzipped and that everything inside it was unzipped as well so there is no way to install the plugins.

This is why we strongly recommend renaming the archive (after extracting its contents) to If people do that, they are less likely to navigate to the wrong location from inside calibre.)

I have installed the calibre plugins, but now I get an error “Plugin not configured! Decryption unsuccessful. This may be the first time you’ve used this plugin (or the first time since upgrading this plugin). You’ll need to open the customization dialog (Preferences->Plugins->File type plugins).”

You have an old version of the plugin for Barnes & Noble ePubs installed. Make sure you remove all of the old versions of the plugins after installing the new all-in-one DeDRM plugin.

How do I remove the old plugins?

  • Open calibre
  • Select the menu “Preferences/Change calibre behavior”
  • Select “Plugins” (on the bottom row, green jigsaw-puzzle button)
  • Check the check box “Show only user installed plugins”
  • Click on the “>” arrow in the line: “> File type plugins”
  • For each old plugin in turn,
    • Click on the plugin to select it
    • Click on the remove plugin button
    • Click on OK button in the confirmation dialog
    • If there are more to delete, click on the “>” arrow in the line: “> File type plugins” to re-open the list.
  • Click “Apply” (top left of dialog)
  • Click “Close” (bottom right of dialog)

I have installed the calibre plugin, but my books still have DRM. When I try to view or convert my books, calibre says they have DRM.

The DRM only gets removed when the ebook is imported into calibre. If the book is already in calibre, you must delete the book from calibre and import the ebook again. It is not enough to just import the book again: calibre will discard the newly imported DRM-free version as a duplicate, leaving only the original DRMed version.

I have installed the calibre plugin or I am trying to use one of the other tools, but I don’t know where my ebooks are stored.

Your ebooks are stored on your computer or on your ebook reader. You need to find them to be able to remove the DRM. If they are on your reader, you should be able to locate them easily. On your computer it’s not so obvious. Here are the default locations.


Navigating from your home folder:

Kindle ebooks are in either Library/Application Support/Kindle/My Kindle Content or Documents/My Kindle Content or Library/Containers/ Support/Kindle/My Kindle Content, depending on your version of Kindle for Mac.

Adobe Digital Editions ebooks are in Documents/Digital Editions


Navigating from your Documents folder:

Kindle ebooks are in My Kindle Content

Adobe Digital Editions ebooks are in My Digital Editions

Mobipocket Reader ebooks are in My ebooks

How can I download copies of my Barnes & Noble Nookbooks?

Even though Barnes & Noble has removed the download pages for their older PC and Mac software from their website, the installation files are still currently available on their servers via these direct links:

The downloaded books can be found in Documents/My Barnes & Noble eBooks. There are a few types of books which cannot be downloaded with this software, but they cannot currently be decrypted with the tools. These include Page Perfect Nookbooks (PDFs), enhanced ebooks (i.e. Nook Kids Read-to-me), and many image heavy items (i.e. comics/graphic novels).

Older Nook devices and older versions of the Nook Android app also allow access to the ebook files when connected via USB to your computer.

Be sure to download fresh copies before attempting to remove the DRM, as previously downloaded copies may not have the current encryption even though the device or app can still open them.

I have installed the calibre plugin, and the book is not already in calibre, but the DRM does not get removed.

You must use the exact file that is used by your ebook reading software or hardware. See the previous question on where to find your ebook files. Do not use an old copy you have that you can no longer read.

If you cannot read the ebook on your current device or installed software, the tools will certainly not be able to remove the DRM. Download a fresh copy that does work with your current device or installed software.

I have installed the calibre plugins and the book is not already in calibre, but the DRM does not get removed. It is a Barnes & Noble (nook) ebook.

Barnes and Noble changed the way they generate the decryption key for their DRMed ebooks starting in late 2014, with all accounts apparently being switched over to the new scheme by the end of March 2015.

There are currently two ways to get a decryption key for your Barnes & Noble (nook) ebooks:

  1. Enter your Barnes & Noble account email address and password into the configuration dialog.  The DeDRM tools v6.2.2 or later will use this information to retrieve the decryption key from the B&N servers.  The email address and password will not be stored.
  2. Install Nook Study (Windows download, Macintosh download), and download your ebooks through that. The DeDRM tools v6.2.0 or later will pick up the decryption key from the Nook Study log files automatically.

I have installed the calibre plugin, and the book is not already in calibre, but the DRM does not get removed. It is a Kindle book.

If you are on Windows 8 or newer and using the Windows Store Kindle app, you must download and install the Kindle for PC application directly from the Amazon website. The tools do not work with the Windows Store Kindle app.

If this book is from an E-Ink Kindle, you must enter the serial number into the configuration dialog. The serial number can be found on the device information screen under settings.  However, the easiest way to enter it into the configuration dialog without typos is to copy and paste it from the “Manage Your Content and Devices” page on the Amazon website.

If this book is from Kindle for Mac or Kindle for PC, you must have the Kindle software installed on the same computer as your copy of calibre.

If the book is from Kindle for PC or Kindle for Mac (version 1.17 or older) and you think you are doing everything right, and you are getting this message, it is possible that the files containing the encryption key aren’t quite in the format the tools expect. To try to fix this:

  1. Deregister Kindle for PC(Mac) from your Amazon account.
  2. Uninstall Kindle for PC(Mac)
  3. Delete the Kindle for PC(Mac) preferences
    • PC: Delete the directory [user folder]\AppData\Local\Amazon (it might be hidden) and [user folder]\Documents\My Kindle Content
    • Mac: Delete the directory [home folder]/Library/Application Support/Kindle/ and/or [home folder]/Library/Containers/ Support/Kindle/ (one or both may be present and should be deleted)
  4. Reinstall Kindle for PC(Mac)
  5. re-register Kindle for PC(Mac) with your Amazon account
  6. Download the ebook again. Do not use the files you have downloaded previously.

Some of my books had their DRM removed, but some still say that they have DRM and will not convert.

There are several possible reasons why only some books get their DRM removed.

  • You still don’t have the DRM removal tools working correctly, but some of your books didn’t have DRM in the first place.
  • You added your books to calibre in large batches. For some unknown reason, sometimes calibre stops using the plugin after a while on a single import. Delete the books that still have DRM and import them into calibre in batches of twenty.
  • Kindle only: The problem book is in the Topaz format and contains some coding that the tools do not understand. You will need to get a log of the deDRM attempt, and then send the book and the PID (shown in the log) for the book to Apprentice Harper, so that the tools can be updated. Please open a new issue over at the GitHub repository.
  • Kindle only: The problem book is in the KFX format which has not been reverse-engineered yet. To get the book in a format the tools can decrypt, either download the book with Kindle for PC/Mac version 1.17 (or earlier) or go to the Manage Your Content and Devices page at Amazon and choose “download and transfer via USB” for an E-ink Kindle (enter its serial number into the tool’s customization).

If you are still having problems with particular books, you will need to create a log of the DRM removal attempt for one of the problem books, and post that in a comment.

I didn’t use to have any problems with the tools and my Kindle ebooks, but now I’m getting .azw3 files instead of .mobi files.

Amazon have introduced a format called KF8 which the tools identify by giving the extension .azw3. Recent versions of calibre know about .azw3 files and can convert them to Mobipocket or ePub. To view .azw3 files with calibre it is necessary to tell calibre to use its internal viewer for .azw3 files in calibre Preferences/Change calibre behaviour/Behaviour/.

Do the tools work on books from Kobo?

Kobo uses Adobe Digital Editions encryption, but it also uses its own application and encryption system, so you might not have already installed Adobe Digital Editions. Version 2.0.1 (download here) is strongly recommended. Version 3.0 and later are capable of utilizing a new encryption scheme which the tools cannot unlock.

Once you have installed ADE 2.0.1, you must authorise it with an Adobe ID. Failing to do that will link your DRMed ebooks to this particular installation of ADE, instead of to an ID that can be used with any new installation. Do this before you try getting any DRMed ebooks loaded into Adobe Digital Editions. (Help menu/Authorize Computer… Choose Adobe ID for “ebook Vendor” and enter your Adobe ID and password. Adobe ID is usually your email address.)

After you have installed ADE 2.0.1 and authorised it with an Adobe ID:

You can find all your Kobo books in your library on the Kobo website.

Some are already DRM-free and have a blue “DOWNLOAD EPUB” (or PDF) button.

Those with Adobe DRM have a blue “ADOBE DRM EPUB” (or PDF) button.

Clicking on the “ADOBE DRM EPUB” (or PDF) button downloads an ‘.acsm’ file. This is a link file used by Adobe Digital Editions to download the actual epub or pdf file, and it is at this point that the DRM gets applied for your installation of Adobe Digital Editions.

Make sure your installation of ADE 2.0.1 is authorised to your Adobe ID before proceeding. Open the ‘.acsm’ file with Adobe Digital Editions 2.0.1, and the ePub or pdf file will download. See Where are my ebooks? above to find the location of the downloaded ADE epub or pdf. You can now use whichever of the DeDRM removal tools is most convenient for you on this file to obtain your DRM-free book.

Alternatively, you may use the Obok calibre plugin to remove DRM from Kobo books downloaded with the Kobo Desktop application (not the Windows Store app) or on an attached E-Ink Kobo reader (but not a Kobo Arc or Kobo Vox). If both are available, ebooks will be read from the attached E-Ink Kobo reader. To import from the desktop application, unplug the Kobo reader. See the Readme file inside the Obok_calibre_plugin folder of the tools archive for further instructions.

Do the tools work on books from the Google Play store? Or other stores with Adobe DRM?

Google Play books can be downloaded from My Books at the Google Play books website. Click the menu button (3 vertical dots) for the book that you want and chose Download EPUB or Download PDF.

Other ebook stores which use Adobe DRM should have a page on their website where you can download your book files. Look for My Library or My Books while signed into your account.

As described in the answer about Kobo ebooks above, you will first download ‘.acsm’ files which should be opened with Adobe Digital Editions 2.0.1 (authorised with your Adobe ID) to obtain the actual epub or pdf book.

I cannot solve my problem the DeDRM plugin, and now I need to ‘post a log’. How do I do that?

First, remove the DRMed book from calibre. Then look under the Preferences menu for ‘Restart in debug mode.’ After calibre reopens, import your book and then close calibre. A text log of the import will automatically open. Paste the information into a comment on the main post.

I cannot solve my problem with one of the DeDRM applications, and now I need to ‘post a log’. How do I do that?

On Macintosh, the DeDRM application creates a log file on your desktop every time it is run. Copy the contents of that (it is a simple text file) and paste it into your comment.

On Windows, the DeDRM application creates a log file in your user directory every time it is run. Copy the contents of that (it is a simple text file) and paste it into your comment.

Why don’t the tools work with Kindle Fire ebooks?

The Kindle Fire is Android based unlike any of the earlier standalone Kindles and the current tools will not work with ebooks from Kindle Fire devices.

Your only workaround is to install Kindle for PC or Kindle for Mac and use books from there instead.

Why doesn’t the UDID of my iOS device work for my Kindle for iOS ebooks?

Unfortunately, for most people, the tools no longer work with ebooks from the Kindle for iOS application. This is because Apple no longer allows applications to use the UDID, and so Amazon can’t get access to it.

Some long-term users of the iOS application may find it still works, because Amazon still has a note of their UDID from before the ban came into operation. New installations definitely won’t work.

Your only workaround is to install Kindle for PC or Kindle for Mac and use books from there instead.

Do the tools work on books from the Apple iBooks Store?

Books from Apple’s iBooks Store use a variant of Apple’s Fairplay DRM and therefore the tools in the main tools archive will not work with these ebooks. The only tools previously known to work for these books was Requiem version 3.3.6 by Brahms. See this post for more details.  Unfortunately, I am unaware of any tools currently capable of removing DRM from Apple’s iBooks.

I’ve got the tools archive and I’ve read all the FAQs but I still can’t install the tools and/or the DRM removal doesn’t work

  • Read the ReadMe_First.txt file in the top level of the tools archive
  • Read the ReadMe file in the folder of the tools you want to use.
  • If you still can’t remove the DRM, ask in the comments on the main post of this blog, reporting the error as precisely as you can, what platform you use, what tool you have tried, what errors you get, and what versions you are using. If the problem happens when running one of the tools, post a log (see previous questions on how to do this).

General Questions

Once the DRM has been removed, is there any trace of my personal identity left in the ebook?

The tools only remove the DRM. No attempt is made to remove any personally identifying information.

What are Kindle Topaz ebooks? HTMLZ? SVG?

Most Amazon Kindle ebooks are Mobipocket format ebooks, or the new KF8 format. However, some are in a format known as Topaz. The Topaz format is only used by Amazon. A Topaz ebook is a collections of glyphs and their positions on each page tagged with some additional information from that page including OCRed text (Optical Character Recognition generated Text) to allow searching, and some additional layout information. Each page of a Topaz ebook is effectively a description of an image of that page. To convert a Topaz ebook to another format is not easy as there is not a one-to-one mapping between glyphs and characters/fonts. To account for this, two different formats are generated by the DRM removal software. The first is an html description built from the OCRtext and images stored in the Topaz file (HTMLZ). This format is easily reflowed but may suffer from typical OCRtext errors including typos, garbled text, missing italics, missing bolds, etc. The second format uses the glyph and position information to create an accurate scalable vector graphics (SVG) image of each page of the book that can be viewed in web browsers that support svg images (Safari, Firefox 4 or later, etc). Additional conversion software can be used to convert these SVG images to an image only PDF file. The DeDRM and Kindlebooks tools from this site provide both versions of the Topaz ebook so that the user can choose which one to use. The K4MobiDeDRM plugin only produces the html version of the ebook. The html version can be manually cleaned up and spell checked and then converted using Sigil/calibre to epubs, mobi ebooks, and etc.

I’ve bought Mobipocket ebooks from an on-line retailer without having to enter the PID of my copy of Mobipocket Reader, and I can read them in Mobipocket Reader. But when I try to convert them to another format, calibre says that they have DRM, but the tools say they don’t contain a PIDs, and I should open them in Mobipocket Reader. What’s going wrong?

The books are downloaded without a PID, but still encrypted. Opening them in Mobipocket Reader causes Mobipocket Reader to create a copy of the ebook that contains with the Mobipocket Reader’s PID. This copy is stored in the My ebooks folder in your Documents folder. It’s this copy that you must use with the DRM removal tools.

Are the tools open source? How can I be sure they are safe and not a trojan horse?

All the DRM removal tools hosted here are almost entirely scripts of one kind or another: Python, Applescript or Windows Batch files. So they are inherently open source, and open to inspection by everyone who downloads them. The source for any compiled pieces are provided right inside the tools themselves.

I have an old encrypted PDF file that won’t open in Adobe Digital Editions, how can I remove the DRM?

If your PDF ebooks cannot be read in Adobe Digital Editions, the tools here cannot help. They are probably encrypted using the Content Server 3 (or earlier) methods which Adobe no longer support, not even to allow conversion to Content Server 4 (AKA Adobe Digital Editions).

See for more details.

Adobe only allowed a nine month window (March-December 2009) for migration to Adobe Digital Editions after the Content Server 3 servers were discontinued.

You might be able to find tools to remove the DRM from other sites, but there are several different old encryption schemes for PDF files, and I’m unfamiliar with them. Tetrachroma’s blog might be a good starting point for Windows users, as he’s done a lot of work on some PDF DRM scheme called ‘File Open’.

What ebooks do these tools work on?

The tools linked from this blog remove DRM from PDF, EPUB, eReader, Mobipocket, KF8, Print Replica and Topaz format ebooks using Adobe Adept, Barnes & Noble, Amazon and eReader DRM schemes.

Note these tools do NOT ‘crack’ the DRM. They simply allow the book’s owner (and only the book’s owner) to use the encryption key information already stored someplace on their computer or device to decrypt the ebook in the same manner the official ebook reading software uses.

Microsoft LIT format ebooks using Microsoft’s DRM scheme can have the DRM removed using ConvertLit from

Apple’s Fairplay DRM scheme, used on most ebooks bought at Apple’s iBookstore could previously have the DRM removed using Requiem. See my post Apple and ebooks: iBookstore DRM and how to remove it for more details.  Unfortunately, I am unaware of any tools currently capable of removing DRM from Apple’s iBooks.

Who wrote these scripts?

The authors tend to identify themselves only by pseudonyms:

  • The Adobe Adept and Barnes & Noble scripts were created by i♥cabbages
  • The Amazon Mobipocket and eReader scripts were created by The Dark Reverser
  • The Amazon K4PC DRM/format was further decoded by Bart Simpson aka Skindle
  • The Amazon K4 Mobi tool was created by by some_updates, DiapDealer and mdlnx
  • The Amazon Topaz DRM removal script was created by CMBDTC
  • The Amazon Topaz format conversion was created by some_updates, clarknova, and Bart Simpson
  • The DeDRM all-in-one AppleScript application was created by Apprentice Alf
  • The DeDRM all-in-one Python application was created by some_updates
  • The DeDRM all-in-one calibre plugins was created by Apprentice Alf, based on plugins created by DiapDealer
  • The Scuolabooks tool was created by Hex
  • The Microsoft code was created by drs
  • The Apple DRM removal tool was created by Brahms

Since the original versions of the scripts and programs were released, various people have helped to maintain and improve them, mainly some_updates, DiapDealer, Apprentice Alf, and Apprentice Harper.