Proofing Your Ebook Files

Your ebook comes in two file types: an EPUB file and a MOBI file. The MOBI file is compatible with most Kindle devices and apps (see info below about Kindle file formats)  and can be uploaded to a Kindle Direct Publishing account for distribution on Amazon. The EPUB file is compatible with the majority of other devices and apps, including iBooks, Nook, Kobo, and Google Play. The EPUB file has been coded to meet the standards of EPUB 3.0 set by the International Digital Publishing Forum, the standards required by most ebook stores and ebook distributors. If your distributor has requirements beyond IDPF standards, let me know so that I can adjust the file accordingly.

The easiest way to proof the EPUB file is to either open it in iBooks on any Apple device or in the latest version of Adobe Digital Editions on PC.

The best way to proof the MOBI file is open it in a Kindle desktop app or to load it directly to a Kindle device. Alternatively, you can download and use Kindle Previewer. No matter which program or device you use, some features like Enhanced Typesetting will not be enabled due to the fact the they work only in books purchased directly through Amazon. Regardless, you will get a pretty good idea of what the final product will look like.

Note about Kindle file formats: Your MOBI file, which was generated using Kindle’s conversion software, actually contains two book files in one: a KF8 file and a MOBI7 file. The KF8 file is what gets opened in Kindle Fire, Kindle Android apps, Kindle desktop apps, and the more recent generations of Kindle e-ink devices. The MOBI7 gets opened in older e-ink devices. To complicate matters, Kindle uses a file format called AZK for iOS devices (iPhone, iPad). The ASK type closely resembles the KF8 file, but is only generated after the book is uploaded to Kindle for sale on Amazon. When someone buys your book on Amazon, Amazon will deliver the correct file type to the reader’s device or app. Although you can open the MOBI file on an iOS device, it will not accurately reflect what the book will look like. The best you can get for that is to open the file in Kindle Previewer and select Phone from the Device Type preview menu.

Before you proof the files, here are some important things to note about ebooks:

  • Unlike print books in which typefaces and font sizes are fixed, ebooks give readers the choice to use whichever typefaces and font sizes the app or device allows. Although it is possible to code an ebook to include the same typefaces used in a print book, there are no guarantees the app or device will use them. In fact, many will suppress this option and use only the typefaces native to the device or app. For this reason, it’s best not to get hung up on if a heading or portion of text doesn’t look just like it does in the print book. It often can’t. What matters is that headers are clearly headers and that text offset from the main body text in some way is still visually distinct, regardless of the typeface.
  • Page breaks, line breaks, and chapter breaks are likely to fall in places they don’t in the print book. This is unavoidable. Each device or app has a different screen size, meaning some (like those on smart phones) will have fewer words per page and some (like those on tablets) will have more. These factors make it difficult to predict where breaks will fall.
  • Many people who read ebooks have strong preferences for how the text is justified (either fully justified [the text aligned on both the right and left margins] or left justified [the text aligned on the left margin and ragged along the right margin]). Most e-reading apps and devices default to fully justified text unless the option is disabled by the reader. To ensure the text is rendered as left justified when the option for fully justified text is disabled, the file itself needs to be coded as left justified. The ebooks I produce follow this standard. If you want to switch between fully justified and left justified text when proofing the book, play around with the justification or text settings of your app or device.
  • Image placement can also be problematic. Depending on the size of the screen the ebook is read on, the placement of an image might force an odd page break to occur. Again, this is often unavoidable. What matters is that the image itself is viewable on the screen.
  • E-reading apps and devices vary in how they render the same ebook file. One might do a stellar job of displaying an embedded list (a list within a list) while another might not display it in such a way that it looks like an embedded list at all. If one app or device doesn’t display special formatting well while others do, the problem is likely with your e-reader’s settings, not with the ebook file. Try playing with the settings to see if you can get a better result. If you can’t, it might be possible to adjust the file to compensate, but there are no guarantees.
  • Most ebooks will have two hyperlinked navigation aids that each function as a table of contents. These are often referred to as the logical TOC and the HTML TOC. The logical TOC is required by most ebook stores. This aid is typically displayed in a window to the side of the main text or in a pop-up window when you click on a button at the top of a page. It typically links to the start of each chapter. The visual appearance of the logical TOC is defined by the app or device you are using. The HTML TOC is placed within the book and closely mirrors the TOC in the print version of the same book. This TOC is optional but strongly recommended, especially for nonfiction books. This TOC can be formatted to match the appearance of the rest of the ebook text. It can also contain more (or fewer) links than the logical TOC. For example, the logical TOC might have links to just the start of each chapter, but the HTML TOC can link to all levels of subheads within the chapter.

When proofing your ebook, here’s what to look for in addition to any typos that might be lingering:

  • Make sure all hyperlinks in the table of contents go to the correct chapters.
  • Make sure all hyperlinks within the text are clickable and point to the correct website or email address.
  • If your book has footnotes or endnotes, make sure all note references are clickable and point to the correct note.
  • Check all images for clarity.

I have already gone through the above list on my own, but it’s still wise for you to do your own proofing for quality assurance.

If you find something that needs to be fixed, the two best ways to alert me are to either send me a screen shot of the problem or send me a description of the error referencing the chapter title and opening words of the paragraph that contains the error.