Reflowable vs Fixed-Layout: Choosing an Ebook Format

Before any styling decision, ebook production forks one way or the other: reflowable or fixed-layout. It determines how the book behaves on every device, what you can and can't control, and how much production work the book needs. Picking the wrong one usually means redoing the file.

Reflowable: text that adapts to the reader

In a reflowable ebook, the reader controls the experience — font, size, line spacing, margins, light or dark mode — and the text flows to fit whatever screen it's on. There are no fixed "pages"; there are locations. This is the right default for novels, memoir, and most non-fiction: books that are read linearly and are mostly words.

• Strengths — accessible by default, small file size, works identically on a phone, an e-reader and an app, and respects the reader's settings.
• Limits — you cannot guarantee where anything lands; complex tables, side-by-side figures and precise page composition don't survive reflow.

Fixed-layout: the page is the design

A fixed-layout ebook pins every element to a page of a set size, like a PDF that can still carry interactivity. It's built for books where the layout is the content: children's picture books, cookbooks, photography and art books, comics and graphic novels, highly designed textbooks.

• Strengths — full control of composition, typography and image placement; design integrity across devices.
• Limits — large files, weaker accessibility, text often doesn't resize, and the reading experience on a small phone can be poor. Production cost per page is much higher.

The ebook and the print file are not the same job

A common mistake is treating "the PDF we sent to the printer" as the ebook. Print is inherently fixed — trim size, margins, gutter, page breaks. A reflowable ebook throws most of that away on purpose. Even for a fixed-layout ebook, the page geometry that works in print rarely maps one-to-one to a screen aspect ratio. Plan for two outputs from one source, not one file reused.

How to decide, quickly

Choose reflowable if the book is read start to finish and would still make sense as plain text. Choose fixed-layout if a reader flipping to any single page would lose meaning by having the design stripped away — or if images and text must stay locked together. If you're genuinely between the two, reflowable is the safer, cheaper, more accessible default, and you can offer a print or PDF edition for readers who want the designed version.