Three Book File Formats Every Self-Published Author Should Understand

After you have finished writing, editing and formatting your manuscript, you need to prepare the correct file format for publishing.

There are three common types of book files you should know about.

EPUB: For Kindle and Other Ebook Stores

EPUB is one of the most widely used ebook formats. It is accepted by Amazon KDP, Google Play Books, Apple Books, Kobo and many other ebook retailers.

For ordinary text-based books, EPUB uses a feature called reflowable text. This means the text automatically adjusts to fit the reader's screen, whether they are using a smartphone, tablet or ebook reader.

Readers can usually change the font type, font size and line spacing to suit their preferences.

Unlike a printed book, a reflowable EPUB does not have fixed page numbers, running headers or footers. The number of pages displayed can change depending on the device and reading settings.

You can preview your EPUB using Amazon's free Kindle Previewer software before uploading it to KDP.

For Amazon KDP, there is no need to insert the cover into your EPUB manuscript because Amazon automatically adds the cover uploaded separately. However, Google Play Books requires the front cover image to be included in the EPUB file.

PDF: For Ebooks With a Fixed Layout

PDF is another popular ebook format, especially when you want the book to look exactly as you designed it.

Unlike reflowable EPUB, a PDF preserves the position of the text, images, margins and page numbers.

This makes it suitable for workbooks, manuals, illustrated books and other publications where the page layout matters.

When preparing a PDF ebook for reading on a screen, I usually use equal left and right margins. I also include the front cover as the first page.

The disadvantage is that readers generally cannot adjust the font size without zooming in, which can make a PDF uncomfortable to read on a small smartphone.

Google Play Books accepts both PDF and EPUB. In fact, Google recommends uploading both formats when possible, so readers have more options.

PDF is also useful when you sell ebooks directly through your own website or platforms such as Payhip or Gumroad.

Print-Ready PDF: For Paperback Books

A paperback is a physical book with a soft cover.

Although its interior is commonly supplied as a PDF, the formatting requirements are different from those of a screen-reading PDF ebook.

The most important difference is the margins.

In a paperback, the inside margin, also called the gutter-side margin, needs sufficient space for binding. This prevents text from disappearing too close to the spine.

The inside and outside margins alternate on facing pages.

In a conventional left-to-right paperback, odd-numbered pages appear on the right, while even-numbered pages appear on the left.

Page numbers, running headers, chapter openings and blank pages also need to be handled carefully.

Another important consideration is the trim size, which is the final physical size of your book, such as 6 x 9 inches.

For Amazon KDP paperback publishing, I recommend submitting the interior as a print-ready PDF.

Do not include the book cover in the interior PDF. The full paperback cover, consisting of the front cover, spine and back cover, is prepared and uploaded separately.

My Advice to New Authors

If you intend to publish your book in both ebook and paperback editions, prepare separate files for each format.

For a typical nonfiction book, I recommend:

• EPUB for ebook stores such as Amazon Kindle, Google Play Books and Kobo.
• Screen-friendly PDF for direct sales on your website
• Print-ready PDF for paperback publishing.

One final tip: Always inspect your finished files before publishing. Formatting errors are much easier to correct before readers discover them.

A good book deserves good formatting. It makes reading more comfortable and gives your work a professional appearance.

Need Help Formatting Your Book?

I provide professional book layout and formatting services for SGD $100.

The fee covers interior formatting only. Cover design, editing and proofreading are available at an additional charge.

You will receive your completed book in three formats:

• EPUB for Kindle and other ebook stores.
• PDF ebook for reading on screen or selling directly.
• Print-ready PDF for paperback publishing.

Delivery within 24 hours.

You provide the completed manuscript. I'll handle the formatting and prepare all three files for publishing.

Interested? Send me a private message at samchoo@gmail.com