How to Put Non-Amazon Ebooks On Your Kindle

Amazon and Macmillan have been in a pissing match recently over ebook pricing. On Friday, as part of their continuing battle, Amazon removed the “Buy It Now” button from all Macmillan titles in their catalog, even the print ones. The only way you could buy a Macmillan title through Amazon was through one of the Amazon Marketplace sellers.

As you can imagine, authors weren’t happy.

By Monday Amazon had given in and started re-instating the “Buy It Now” button on Macmillan titles, though they’re taking their time doing so. Meanwhile, lots of people on the internet are happily choosing to be on Team Amazon or Team Macmillan, since you want to choose which giant company will crush your dreams instead of having one forced on you. They’re also parsing the meaning of words like monopoly, monopsony, and collusion. It’s very exciting!

In the wake of what was a pretty stupid attempt by Amazon to muscle Macmillan, some have said that they don’t want to buy books from Amazon, but they bought a Kindle. What are they to do?

Since I’m a physicist and thus have a technical answer to any question, even “Who should I date?” (answer: the robot, for he is programmed to love you always), let me explain how you too can put non-Amazon ebooks on your Kindle.

The big thing you’ll need is a copy of Calibre. Calibre is free software that runs on Windows, Macs, and Linux. It’s the Swiss Army knife of ebook software. It’ll manage your entire library if you want, but the most important feature in this case is that it can convert ebooks from one format to another. The Kindle uses a modified version of the Mobipocket format (files that end in .mobi or .prc), so that’s the format you’ll convert to. (Calibre’s frequently-asked questions has an entire section on converting an ebook to different formats.

The big question when buying an ebook is: Does it have DRM? DRM, or Digital Rights Management, is a scheme where the ebooks are locked so that they can only be opened by a specific ebook reader or piece of software.

No DRM: you can buy the book in nearly any format you want, though Mobipocket is best. If you buy the book in a different format (such as ePub or HTML), use Calibre to convert it to Mobipocket format. Once you’ve done that, you can plug your Kindle up to your computer and drag the files onto your Kindle.

DRM: Ooh, now it’s going to get tricky. You need to buy your ebook in Mobipocket format, and you have to jump through some hoops to make it readable on your Kindle.

Mobipocket DRM uses something called a PID key. The PID is a unique string that identifies a specific reader. Your Kindle has one that’s based on its serial number. You can find out your serial number by looking on the back of your Kindle (for some models), checking the box it came in (it should have a sticker on it with your serial number), or going to your Kindle’s “Settings” screen and typing “411” (without quote marks). To turn that serial number into a PID, you can use this online tool. (Alternatively, you can download a python script called to find out what your PID is, if you’re a Python kind of person.)

When you buy a DRM-protected Mobibook, you’ll be asked for your PID. Enter your Kindle’s PID and download the file. What happens next depends on your operating system and whether you want to get rid of the DRM entirely.

Are you on a Mac? If so, you can use Mobi2Kindle to convert your ebook to a protected format that your Kindle will read. This won’t get rid of the DRM, but it will make the book readable on your Kindle.

Are you running Windows? If so, you can use the unswindle package (as described here) to remove the DRM and create an unprotected Mobipocket book that your Kindle will read with no problem.

Are you on Linux, or on a Mac and want to get rid of the DRM altogether? If so, you’re going to have to do some Python hacking! You’ll need a copy of to remove the DRM so that you can read the book on your Kindle. The process is a bit complicated; fortunately, there’s a guide to help you out.

How can I tell if it has DRM or not? The best way is to try to purchase a Mobipocket format book. If you need to enter a PID to do so, you’re buying a DRM-protected book. Chances are, you’re going to be buying a book with DRM on it.

There you go. You now can read non-Amazon ebooks on your Kindle.