eBook Formats
Which formats does my e-reader support? Where can I find compatible eBooks for my e-reader?
The already large number of eBook formats can quickly confuse newcomers in particular: Which formats can my eBook reader read? Where do I get the right eBooks for my eReader? And how do I convert eBooks into formats my eBook reader can read?
This section provides a brief overview of the most important eBook formats. Additional articles in our “Help” section cover compatibility, eBook stores, and how to correctly convert eBooks.
Note: You can find basic information (definition, options, pros & cons, etc.) about eBooks here.
Which eBook format do I need?
Which eBook formats are important to me?
Three eBook formats have emerged that are suitable for and available on different devices.
EPUB is the most common eBook format and is supported by almost all eBook readers. It’s an open standard that, in its latest version, also supports many different text formatting options and multimedia enhancements (images, music, etc.). At present, however, ePub eBooks are mostly regular text-based books.
Alongside the ePub format, the PDF file format is also widespread. It’s now very often used for documents made available on the internet. However, because PDF files contain fixed layout specifications (font size, paragraphs, spacing, etc.), they’re often only a limited fit for eBook readers.
With the AZW format, Amazon serves its customers. AZW is used only by Amazon, i.e., no other reading device can open Amazon eBooks without conversion or a dedicated app. The reverse is also true: Amazon Kindle devices cannot read ePub files. The AZW format is based on the MOBI format, which enjoyed broader support a few years ago. Unlike the AZW format, MOBI is openly accessible, so you’ll still find this file type in some other eBook stores.
With the release of the third Kindle Paperwhite, Amazon also introduced the improved font options in mid-2015 along with the KFX format. Like AZW files, the new format isn’t supported by any other provider, even though it (presumably) is also based on the MOBI standard. Amazon delivers KFX eBooks alongside the AZW format – which file you receive depends on the eReader software or the version of the Kindle app. The newer the app or device, the more likely you are to receive KFX files.
In addition to these three (or four) common eBook formats, many reading devices can also display various authoring formats such as Word, TXT, RTF, and others. However, these are generally not used for selling eBooks and therefore play only a minor role. There are also dedicated file formats for comic and anime fans. CBZ or CBR are often used here alongside PDF and simple image files. However, only a few devices support these formats.
Which device for which format?
When buying an eBook, what matters is which eBook reader you own. As long as it’s not a Kindle, you usually can’t go wrong buying an ePub file. To be safe, you should always consult the device’s user manual if you’re unsure. It normally contains an overview of all supported file formats. You’ll also find a detailed list of the formats supported by each device in our eBook Reader overview and in the eBook Reader comparison.
You can buy eBooks either in various online stores on the internet, or often directly on the reading device. But the purchase alone isn’t enough, because digital books almost always have built-in copy protection. This copy protection is called “Digital Rights Management,” or “DRM” for short. The books are tightly linked to a user, so they can only be read on a limited number of different devices. To link the eBook to the reader and authorize its use, you often need an additional program on your PC (Adobe Digital Editions, or ADE for short). If you use a reader’s integrated eBook store, this step is sometimes omitted.
In contrast, books that are not covered by copyright (e.g., because the rights have expired, as with Jane Austen, Charles Dickens, and others) are freely accessible and can be reproduced. ePub or PDF are generally used here. You’ll find a large selection of providers of such books in our free eBooks collection.
Another key difference lies in the properties of the format itself. These differ in how the above-mentioned DRM can be implemented, how graphics are displayed, whether sound files can be embedded, or whether bookmarks can be set. The rendering, in particular, also varies from device to device. Proprietary eBook formats such as Amazon’s AZW, for example, are tailored to Kindle eBook readers and work smoothly there. Formats like PDF, which is popular for documents, cause many eBook readers more trouble, especially if they haven’t been converted for the typical 6-inch eBook size and are designed for other dimensions (e.g., A4) than the eReader’s display allows.
If your own eBook reader can’t handle a format, that doesn’t necessarily have to be a problem. Our eBook conversion section shows how to convert documents into a compatible format. However, this only applies to DRM-free files. If you want to convert DRM-protected files, you need to remove the DRM first. Unfortunately, we can’t describe how that works here due to the legal situation. You can find more information on removing DRM here.
Summary
In summary, the eBook market can roughly be divided into three (or four) formats:
- ePub
- AZW (+ KFX)
Right now, Amazon’s AZW format probably offers the easiest path to hassle-free reading. That’s not due to the format itself, but to Amazon’s distribution model. The devices are linked directly to the buyer’s Amazon account, so during initial setup and when you purchase more eBooks, there’s hardly anything you need to take care of. In other words, you’re not forced through an annoying initial DRM setup. However, with Kindle devices and the AZW format you’re very tightly bound to Amazon. If you want to buy an eBook from another store, that’s not easily possible. Critics often point this out.
eBook readers from other manufacturers (e.g., Tolino, Sony, Kobo, PocketBook, etc.) offer significantly more freedom here. You can choose to buy eBooks directly on the device (if supported) or from any bookseller you like. The advantages are obvious: if another store promotes special offers and prices, you can take advantage of them without any hassle. The selection also differs in part quite a bit, so you won’t always find the eBook you want at every retailer.
Buying PDF eBooks is generally not recommended if you want to read them on an eBook reader. The display options are often so limited that you usually can’t read the book properly without converting it. PDF books are typically better off on a PC or tablet. Even 7-inch tablets are already clearly superior to a typical eBook reader here, but larger sizes between 9 and 10 inches make even more sense. Our tablet comparison answers which tablets are suitable.
Format detail lists
For detailed technical information on the individual file formats:
Detailed list of eBook formats
Feature and compatibility comparison
On Wikipedia you can find overviews of the key features of the file formats as well as their compatibility with the most important eBook readers.
You can find details on the individual readers in our eBook Reader overview.
