Updated 2026: PRC is a legacy Kindle format. From Kindle for Android V7.2 onward, all downloaded Kindle files are in KFX format instead — you'll only encounter PRC if you're using an older Kindle for Android version, or reading older files you downloaded years ago.
If your books are downloading in KFX format, please see our KFX DRM removal guide instead.
What Is a PRC File, and Why Does Kindle Use It?
PRC didn't start out as an eBook format at all. The extension originated on Palm OS, where it was used as a general-purpose container for applications, localized resources, and shared libraries — not unlike how a .zip file can hold almost anything. Palm OS only recognized two file extensions system-wide, .prc and .pdb, so when the Mobipocket Reader came along in the early 2000s and needed a way to distribute eBooks on Palm devices, it had no choice but to package them as .prc files as well.
Under the hood, a PRC eBook and a MOBI eBook are the same file structure. Both start with a variable-length book title, followed by the eight-byte marker "BOOKMOBI" that identifies the file's type and creator. The only real difference between a .prc and a .mobi file is the extension on the end — which is why Calibre treats the two formats identically, importing a .prc file straight into your library as a MOBI book with no conversion needed.
PRC's connection to Kindle goes back to 2005, when Amazon acquired Mobipocket outright. That acquisition is what brought Mobipocket's compression and formatting technology — PRC included — into Amazon's own Kindle devices and software. Kindle's early AZW format was, in essence, a DRM-locked variant of the same Mobipocket format. From there, the format lineage continued: AZW gave way to AZW3 (KF8) when the Kindle Fire launched in 2011, adding HTML5/CSS3-style layout support, and AZW3 has since been succeeded by KFX, the format Kindle has used since around 2015 for most new content.
Can You Still Use PRC Files Today?
Amazon quietly closed the door on new PRC content in 2022, when it removed MOBI/PRC support from the Send to Kindle service entirely. EPUB is now the format Amazon recommends for anything you want to add to your Kindle library going forward.
That said, if you already have older PRC files sitting on your computer or an old Kindle e-reader, they haven't stopped working. DRM-free .prc files still open fine in Calibre (which reads them as MOBI), as well as in apps like FBReader, Cool Reader, and Moon+ Reader. The format itself isn't broken — it's simply no longer the format new Kindle content arrives in.
How to Remove DRM from PRC Files
If your PRC files are DRM-protected — for example, books downloaded through an older Kindle for Android app — you'll need to decrypt them before you can convert or transfer them freely. This is exactly the scenario Epubor Kindle Converter is built for: it works with Kindle for Android running inside an emulator to detect and decrypt your downloaded books, including older PRC-format files, without you needing to manually configure an Android emulator or hunt down old APK versions yourself.
For the full walkthrough — setting up the Android emulator, installing Kindle for Android, and running Kindle Converter to remove the DRM — please follow our step-by-step guide:
» Epubor Kindle Converter User Guide (Android Method)
Download Kindle Converter Mac Apple Silicon
Downloading Kindle Books via PC or Mac Instead?
If you'd rather download your Kindle books using the Kindle for PC/Mac app instead of an Android emulator, your files will be in KFX format, and Epubor Ultimate is the right tool for that job:
» How to Remove DRM from Kindle KFX eBooks
Jonny Greenwood 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.
You have no clue how much i went through trying to figure how to remove the DRM if downloaded from a android device. Works perfectly!
Hi Kenren,
So much glad to hear that my article helps you. And it does encourage to offer more handy stuff to help people read eBooks more freely.
First and foremost, thank you for the guide!
The app seems to just crash on start up on Android 4.4 and above, is that correct?
Does anyone have a new solution to find the PIDs for the last issue of Amazon Kindle for Android on Android 4.4.2 ???
Regards
(also get a patch for 4.8.1.10 but no clue if it's working or not...)
Who originally developed this method? Why are they not keeping it updated?? Amazon now blocks downloading to K4PC for a lot of books, so we need an Android based DeDRM tool now.
but please scan every time from unknown sources.
PID can u see after open the book on menu-info-info-PID List.
I have the EPUBOR for removing DRM, and everything works fine on my Kindle Fire--older version 1.
However, I have several books showing PRC format only, and they won't decrypt. All were purchased directly from Amazon, and sent directly to my KF.
I've read the guide for removing DRM via android devices, but these books were never on an android.
Help!
Hi, the patched kindle app doesnt work on android lollipop and would not logged in on my ICS either. Any update?
Thanks.