A Beginners guide to the pros and cons of flowable vs. fixed ebook file formats

Beginner's guide to the pros and cons of fixed vs. flowable ebook formats

What ebook format do you need?

Before you start formatting it’s important to grasp the difference between file formats, so you don’t waste time creating a book file you don’t need, or isn’t fit for purpose. So today we’re looking at the impact of text layouts on your readers and the pros and cons of choosing the optimal ebook file format for your content.

ebook formats.png — Flowable vs. Fixed ebook file formats

Flowable vs. Fixed Format Ebook Layout

The most popular ebook format is flowable, also known as reflowable, standard, or dynamic, and this is used for text-heavy books where the readers have control over how the content is displayed.

The other ebook format is fixed, which means you design how the book displays and readers can’t change it, except to zoom in and out. The primary reason to choose a fixed format is for books with many images and text that need to be displayed in a specific layout, like a cookery book.

Travel guides can be designed using a flowable format, no matter how many images you are including, but if there are specific elements like information boxes, maps or images that need to be displayed linked to a specific text, then consider using a fixed format. This approach also has its limitations and doesn’t display well on small screens or older ereaders.

Flowable Ebook Layout

The majority of ebooks use a standard ebook layout with flowable text so it can be read on any e-reader, and readers can adjust the font size and style to fit their reading preferences.

The Pros

Flowable layout ebooks are easier, quicker, and cheaper to format.
Text can also be enlarged on screen without losing any essential formatting, making it easily readable on small screens.
Flowable files are smaller, so you can reduce your Amazon delivery fees.
Flowable ebooks can be uploaded to all retailers and aggregators.

The Cons

Standard ebook formats only support single text columns.

Fixed Ebook Layout

Amazon, Barnes & Noble, Kobo, and Apple Books all support derivatives of a fixed-layout file. The EPUB fixed format is EPUB3, whereas the Kindle fixed version is a KF8 file format.

Apple Books, Google Play Books, Kobo, Overdrive, and E-Sentral accept fixed-layout EPUB3 files.
Amazon accepts fixed-layout KF8 files.
Barnes & Noble accepts PagePerfect PDF files.

A fixed-layout file literally fixes content to a digital page, so the content won’t flow across to another page. These books act more like a printed book, where the author is in control of the reader experience, and the reader isn’t able to adjust how their book is displayed.

This ebook fixed-layout may sound strikingly familiar to a PDF layout that is used for a print book file, but the major difference is that a fixed-layout can also include enhanced interactive features that a PDF can’t. Bear in mind only newer ereaders will be able to read and display some of these enhanced features.

The Pros

The author keeps control over how the ebook is displayed on screen, so images and text can be interlocked to a specific point on the page.
It is beneficial if the key element to the book is the design and images, such as in cookbooks, or guide books with a heavy emphasis on images and call-out boxes.
Fixed-layout supports full-bleed internal images, multi-columns, and text that can be placed over or wrapped around images.

The Cons

Given the differences between screen sizes on the hundreds of different ereaders, a fixed-layout ebook might be difficult, or impossible, to read on some smaller screens.
Fixed-layout ebooks don’t give the reader any control over font, spacing, margins, or text size.
Not every e-reader or retailer supports this fixed-layout, and some retailers will not distribute this format, so your distribution will be limited.
Fixed-layout ebooks tend to be larger in file size, so Amazon will charge higher download fees if you choose the 70% royalty rate.
Fixed-layout ebooks are more time consuming to produce and update.

Choose A Flowable Format If:

Your book is predominately text, and any images you include can be positioned between paragraphs, or
You want to reach a broader audience and have your book read on a larger selection of ereaders.

Choose A Fixed Format If:

You want to fix your images to specific positions within your text, place text over images, or have a specific page background color, or
You want to fix a horizontal orientation or have multi-column text on your page.

Understanding MOBI vs. EPUB

The common ancestry of both flowable ebook formats means MOBI and EPUB are similar enough to allow conversion between the two. For example, you can upload an EPUB file to Amazon and it can be converted successfully to MOBI.

You also have the option of using a different file format (Word, for example) and retailers or aggregators will convert your file into their ebook format. For example, Draft2Digital has a free formatting tool that creates your EPUB file, which you can use to upload your ebook to any retailer or aggregator. On the other hand, Smashwords will convert your file, but due to copyright restrictions, you’re not allowed to use their file with a different aggregator.

Kindle’s MOBI Format (Flowable)

The MOBI format (formally known as Mobipocket) is an open standard format based on HTML, which was purchased by Amazon. The key difference between EPUB and MOBI is that files sold by Kindle are locked to devices registered to your account. Amazon recommends KindleGen for the creation of Mobipocket (Kindle) files.

Kindle’s KPF Format (Fixed/Enhanced)

To create a fixed width layout to sell on Amazon, you provide your file in a Kindle Package Format (KPF).

EPUB2 Format (Flowable)

EPUB is an open standard format based on HTML, which means it’s free and publicly available to use. The format standards are maintained by the International Digital Publishing Forum (IDPF), a global standards organization.

The EPUB2 format is the most common ebook format and is widely supported across all platforms. E-reader platforms you can go direct with like Apple Books, Kobo and Barnes & Noble’s Press use EPUB, and when you distribute your book through aggregators you’ll need to upload or convert your base file to EPUB. It’s a flexible format that supports embedded images, bookmarking, highlighting and text-to-speak.

EPUB3 Format (Fixed/Enhanced)

EPUB3 (aka EPUB3FXL) is the latest software version allowing the inclusion of multimedia content like video and audio, but it isn’t supported across all ereaders so the older format still dominates. The enhanced EPUB3 version is also what’s used to create fixed-layout EPUB files with complex formatting without the multimedia content.

Portable Document Format (PDF)

PDFs are the original ebook format read with Adobe Reader (installed on most computers), but because PDF files contain static text, documents can become difficult to read when you view them on a small screen.

Which Book Format Do You Need To Create?

There’s a selection of paid and free tools to create EPUB files from DOC, DOCX, HTML, TXT, RTF, or PDF (there are many more obscure file formats you can use to convert to EPUB, but these are the most popular source file types).

If you create an EPUB file it can be used for all retailers. Amazon will convert it to their proprietary MOBI format before distributing.

Book formatting is fun (well that’s my opinion), but I know the formatting scares many authors, probably because they don’t understand the basics required to get their file created as easily and simply as possible.

Don’t allow fear of formatting get in your way. If you really don’t want to delve into formatting tools and techniques, feel comfortable in the knowledge that just because it’s called self-publishing, doesn’t mean you have to do everything yourself. There are plenty of freelancers on hand to format your book.

What questions do you have about ebook formats and file layouts? Let me know if the comments below.