Your Kindle Supports More Than Just EPUBs And PDFs – Here's Every File Type It Can Read

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As a voracious reader with the lofty goal of transforming into a walking library in my old age, let me give you a piece of advice, one reader to another: don't listen to the hoards of prognosticators suggesting you ditch your Kindle. Amazon's e-reader is an invaluable tool for bibliophiles everywhere. Whether you're looking to take your library on the go, have a partner who despises reading lamps, or are allergic to parchment, a Kindle can reinvigorate even the most dormant reading habits. That is, if you learn to maximize it.

Of course, users can populate their digital library in a variety of ways. But a Kindle Unlimited subscription, or purchasing each e-book through Amazon's store, can get expensive. As such, adept readers have turned to a range of sources when filling their online bookcases. Whether taking advantage of their local library, scouring droves of free online resources, or finding eBooks on a discount, Kindle veterans have gotten creative in populating their digital reading rooms. Of course, Kindle fans also know their favorite e-reader comes with notable drawbacks, especially when venturing beyond the Amazon store, as compatibility issues can easily ruin your latest addition. Notably, Kindles can support 13 formats, listed below:

• Amazon KF10 ebook (.azw, .kfx)
• Amazon KF8 ebook (.azw3)
• Amazon Print Replica ebook (.azw4)
• PDF document (.pdf)
• EPUB ebook (.epub)
• Microsoft Word document (.doc, .docx)
• Plain Text document (.txt)
• HTML page (.htm, .html)
• Rich Text Format document (.rtf)
• JPEG image (.jpg, .jpeg)
• GIF image (.gif)
• PNG image (.png)
• BMP image (.bmp)

To gain a better understanding of these formats, their benefits, and, ultimately, how to use them to maximize your Kindle experience, continue reading our deep dive below.

Let's start with the default formats used by Amazon in its online bookstore. When downloading a book from Amazon, your Kindle will receive it in proprietary formats, which contain DRM protections so the books can't be read by third party e-readers. While older models used KF10, abbreviated as .azw, the Kindle Fire's 2022 release saw the bookseller-turned-tech giant discontinue its support for this format. Instead, Amazon books are now downloaded as a KF8, or .azw3. Amazon print replica books, listed as .azw4, are typically used for textbooks, complex documents, and technical manuals, and function similarly to a PDF.

Things get more complicated when downloading text from third party platforms. Typically, third party books can be transferred to your Kindle via the Send to Kindle function. PDFs and EPUB documents are the most common formats used for eBooks and digital text. Books in EPUB are generally more readable, as the text and formatting adjust to your screen. PDFs, meanwhile, offer many of the same structural benefits when using them on your computer. Users that want to read a word document on their Kindle can download either a .doc or .docx document via the Send to Kindle feature. Meanwhile, readers can send a saved webpage to their Kindle in the form of an html document. TXT provides basic text with minimal formatting, while RTF, or Rich Text Format, delivers basic text formatting.

For images, Kindles support JPEG, PNG, GIF, and BMP images. Which format you choose largely depends on the type of image you want to send. For instance, JPEG is generally better for photographs, while GIF is better for line art.

My first recommendation to upgrade your Kindle experience: go indie. Local bookstores have long been decried as a dying art form – a trend exacerbated by declining literacy rates and the industry's corporate takeover. But using a Kindle doesn't mean abandoning your local mom-and-pop shop. Thanks to retailers like bookshop.org, readers can purchase eBooks from local booksellers. Purchasing eBooks directly from publishing houses is another industry-friendly tactic, cutting out the middle man and giving your hard-earned cash directly to publishers and authors. Bookbub, meanwhile, helps readers find deals on eBooks from major retailers. All these methods are enabled by the Send to Kindle function, allowing users to import eBooks via drag-and-drop file sharing, email, desktop applications, chrome extensions, and their iOS and Android devices. Just make sure the book is in a readable format!

To elevate your Kindle library, take advantage of the open source treasure trove proffered by Project Gutenberg. Founded in 1971, the project is a premier online resource, housing over 75,000 free eBooks. Downloads come in a variety of Kindle-friendly formats, including EPUB, azw3, plain text, and html. If you want to read more modern stories, several free applications enable users to harness their local library's diverse collections. For example, Libby and hoopla are invaluable resources that readers can use to checkout library books for their Kindles. 

Kindle users looking to exert more control over their digital libraries can look to a host of free applications. Calibre, for instance, is an opensource tool that helps users manage the books in their library, including converting books into Kindle-accessible formats. Instapaper, meanwhile, makes your favorite articles and online reads Kindle-friendly.