Answers.Body: <p>The intent of your question seems to be, "Which e-books formats are safe to buy (or obtain legally for free) - such that they will never go obsolete on any future device I use?"</p>
  
  <p>There are actually several approaches to this issue, but you first need to understand a little about DRM (Digital Rights Management):</p>
  
  <p>DRM attempts to prevent illegal copying of books you purchase. DRM creates the following problem for honest consumers: Let's say you buy books protected by DRM from one marketplace. How can you read a book you purchased if you switch to a competitor's device that uses a different DRM scheme for the same or different format?</p>
  
  <p>With that question in mind, here are several approaches you can take to preserving books you obtain for the long haul:</p>
  
  <ol>
  <li>You could elect to stick with the two most popular,
  non-proprietary formats - epubs and PDFs - and never buy books that
  have DRM. Store these books in a sharing service such as Dropbox and
  you'll be able to easily open them on pretty much any desktop or
  mobile device. Even devices that don't have Dropbox will usually
  allow side loading of content when you hook them up to your PC.</li>
  <li>You can mostly do (1) above, but also purchase books that make
  themselves available in the top 3 formats upon purchase (epub, PDF,
  and one of Amazon's 2 formats). Many programming textbooks and
  reference materials can be purchased this way. All purchases I've
  made this way did not have DRM but even if they did have DRM, I
  would be covered.</li>
  <li>You could choose an ecosystem that supports a wide variety of
  hardware and stick with it. For example, Amazon goes to great
  lengths to insure that books you buy from their Kindle store will be
  readable on any Android or iOS device, as well as on a Mac or
  Windows desktop computer. You are not locked in to always buying
  Kindle devices. This is not perfect, however, as you won't be able
  to read the Kindle on hardware that purposely keeps out Amazon
  software, such as the Nook (SimpleTouch, Glowlight). However, if you
  purposely stick to relatively open software platforms (Android, iOS,
  Mac OS X, MS Windows) you won't have an issue.</li>
  </ol>
  
  <p>I personally do a combination of all three. When possible to obtain books for free (legally), I do so, and store it in my dropbox "ebooks" folder. When possible to buy books in multiple formats, I do so. But in instances when I can't do either of these (or book price is so low I don't really care), I purchase from Amazon's book store.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2013-12-23T19:11:32.103Z
Answers.Text: Ta. Will upvote tomorrow when I have some more votes!
Answers.UserDisplayName: Flyk
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2013-12-23T19:08:49.517Z
Answers.LastActivityDate: 2013-12-23T19:08:49.517Z
Answers.UserDisplayName: Joe Golton
Answers.Body: <p>There is an extensive (though maybe not exhaustive) list of ebook formats on <a href="http://en.wikipedia.org/wiki/Comparison_of_e-book_formats">Wikipedia</a>. The article does a comparison on the formats.</p>
  
  <p>The most widely supported formats are <a href="http://en.wikipedia.org/wiki/EPUB">epub</a> and <a href="http://en.wikipedia.org/wiki/Portable_Document_Format">pdf</a> (and <a href="http://en.wikipedia.org/wiki/Mobipocket">mobi/prc</a> / <a href="http://en.wikipedia.org/wiki/Kindle_Format_8#File_formats">KF8</a> / <a href="http://en.wikipedia.org/wiki/Amazon_Kindle">AZW</a> if you include Amazon Kindle). Of course, plain text is probably <strong>THE</strong> most supported format, but I'm assuming you meant something that supports special formatting etc.</p>
  
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Answers.CreationDate: 2013-12-23T18:17:02.513Z
Answers.LastActivityDate: 2013-12-23T18:22:34.910Z
Answers.LastEditDate: 2013-12-23T18:22:34.910Z
Answers.UserDisplayName: Jason Down
Answers.Body: <ul>
  <li><p><strong>EPUB</strong>. An open standard that is supported by most low-cost and free e-readers. But Kindle doesn't support this natively, you have to install a 3rd party reader to read EPUBs on your Kindle device. EPUB v3 supports embedded audio, embedded video, and many more options, but few readers support the fancy 3.0 stuff because it makes the EPUB file so huge. Widely supported by many authoring tools like Pandoc, Calibre, etc.</p></li>
  <li><p><strong>MOBI</strong>. Kindle only. Free authoring tools are generally terrible and very time-consuming fixing bugs and inconsistencies. </p></li>
  <li><p><strong>DJVU</strong>. Another older proprietary format. </p></li>
  </ul>
  
  <p>Any book I get is either EPUB, or I convert it to EPUB. I also use Markdown and Pandoc for authoring EPUB books. It's pretty easy and fast, and it works well.</p>
  
  <p>NOTES: </p>
  
  <ul>
  <li>Any pictures that are color in the EPUB will be rendered as gray scale on B&amp;W screens, like the Kobo Aura H2O.</li>
  </ul>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-11-22T12:33:03.560Z
Answers.LastActivityDate: 2017-11-22T12:33:03.560Z
Answers.UserDisplayName: Bulrush
Body: <p>I am a beginner to eBooks, and as somebody who has been "outside" of eBooks I've only ever heard of Amazon's Kindle and seen a variety of options for purchase on Google Play.</p>
  
  <p>I have recently purchased an Android tablet. If I were to start buying my reading material as eBooks but after having a look at the various reader applications available, it seems they all support a different set of file formats.</p>
  
  <p>What are the different file formats that eBooks are available in and which of these is most widely supported?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2013-12-23T19:35:56.400Z
Comments.Text: What do you mean with most widely supported? Number of different (commercial) files available in that format, number of publishers supporting a format, number of devices, device types or device manufacturers supporting a format?
Comments.UserDisplayName: Anthon
Tags: <file-format><ebook-readers>
Title: What are the different file formats that eBooks are available in and which of these is most widely supported?
UserDisplayName: Flyk
ThreadText: # What are the different file formats that eBooks are available in and which of these is most widely supported?
  
  (Asked by: username_0 on 2013-12-23)
  
  I am a beginner to eBooks, and as somebody who has been "outside" of eBooks I've only ever heard of Amazon's Kindle and seen a variety of options for purchase on Google Play.
  
  I have recently purchased an Android tablet. If I were to start buying my reading material as eBooks but after having a look at the various reader applications available, it seems they all support a different set of file formats.
  
  What are the different file formats that eBooks are available in and which of these is most widely supported?
  
  **Tags:** file-format, ebook-readers
  
  > **Comments:**
  > **username_1**: What do you mean with most widely supported? Number of different (commercial) files available in that format, number of publishers supporting a format, number of devices, device types or device manufacturers supporting a format?  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_2 on 2013-12-23. Score: 4 | Accepted answer
  
  The intent of your question seems to be, "Which e-books formats are safe to buy (or obtain legally for free) - such that they will never go obsolete on any future device I use?"
  
  There are actually several approaches to this issue, but you first need to understand a little about DRM (Digital Rights Management):
  
  DRM attempts to prevent illegal copying of books you purchase. DRM creates the following problem for honest consumers: Let's say you buy books protected by DRM from one marketplace. How can you read a book you purchased if you switch to a competitor's device that uses a different DRM scheme for the same or different format?
  
  With that question in mind, here are several approaches you can take to preserving books you obtain for the long haul:
  
  1. You could elect to stick with the two most popular,
     non-proprietary formats - epubs and PDFs - and never buy books that
     have DRM. Store these books in a sharing service such as Dropbox and
     you'll be able to easily open them on pretty much any desktop or
     mobile device. Even devices that don't have Dropbox will usually
     allow side loading of content when you hook them up to your PC.
  2. You can mostly do (1) above, but also purchase books that make
     themselves available in the top 3 formats upon purchase (epub, PDF,
     and one of Amazon's 2 formats). Many programming textbooks and
     reference materials can be purchased this way. All purchases I've
     made this way did not have DRM but even if they did have DRM, I
     would be covered.
  3. You could choose an ecosystem that supports a wide variety of
     hardware and stick with it. For example, Amazon goes to great
     lengths to insure that books you buy from their Kindle store will be
     readable on any Android or iOS device, as well as on a Mac or
     Windows desktop computer. You are not locked in to always buying
     Kindle devices. This is not perfect, however, as you won't be able
     to read the Kindle on hardware that purposely keeps out Amazon
     software, such as the Nook (SimpleTouch, Glowlight). However, if you
     purposely stick to relatively open software platforms (Android, iOS,
     Mac OS X, MS Windows) you won't have an issue.
  
  I personally do a combination of all three. When possible to obtain books for free (legally), I do so, and store it in my dropbox "ebooks" folder. When possible to buy books in multiple formats, I do so. But in instances when I can't do either of these (or book price is so low I don't really care), I purchase from Amazon's book store.
  
  > **Comments:**
  > **username_0**: Ta. Will upvote tomorrow when I have some more votes!  
  
  ---
  
  ### Answer by username_3 on 2013-12-23. Score: 7
  
  There is an extensive (though maybe not exhaustive) list of ebook formats on [Wikipedia](http://en.wikipedia.org/wiki/Comparison_of_e-book_formats). The article does a comparison on the formats.
  
  The most widely supported formats are [epub](http://en.wikipedia.org/wiki/EPUB) and [pdf](http://en.wikipedia.org/wiki/Portable_Document_Format) (and [mobi/prc](http://en.wikipedia.org/wiki/Mobipocket) / [KF8](http://en.wikipedia.org/wiki/Kindle_Format_8#File_formats) / [AZW](http://en.wikipedia.org/wiki/Amazon_Kindle) if you include Amazon Kindle). Of course, plain text is probably **THE** most supported format, but I'm assuming you meant something that supports special formatting etc.
  
  
  ---
  
  ### Answer by username_4 on 2017-11-22. Score: 0
  
  * **EPUB**. An open standard that is supported by most low-cost and free e-readers. But Kindle doesn't support this natively, you have to install a 3rd party reader to read EPUBs on your Kindle device. EPUB v3 supports embedded audio, embedded video, and many more options, but few readers support the fancy 3.0 stuff because it makes the EPUB file so huge. Widely supported by many authoring tools like Pandoc, Calibre, etc.
  * **MOBI**. Kindle only. Free authoring tools are generally terrible and very time-consuming fixing bugs and inconsistencies.
  * **DJVU**. Another older proprietary format.
  
  Any book I get is either EPUB, or I convert it to EPUB. I also use Markdown and Pandoc for authoring EPUB books. It's pretty easy and fast, and it works well.
  
  NOTES:
  
  * Any pictures that are color in the EPUB will be rendered as gray scale on B&W screens, like the Kobo Aura H2O.
  
  
  ---
  
  