EPUB format decision

Fixed-layout vs reflowable EPUB

Choose reflowable for text that should adapt to readers and screens. Choose fixed layout only when the meaning depends on exact page composition.

Published September 30, 20266 minute read

Definition and decision

What is a fixed-layout EPUB?

A fixed-layout EPUB is an EPUB 3 publication whose pages use a predetermined canvas instead of reflowing to the screen. Use it for picture books, comics and tightly designed educational pages; default to reflowable EPUB for novels, essays, manuals and most text-led books.

Reflowable ebook text changing with screen width while a fixed-layout page retains exact artwork and text positions. — The format decision is a tradeoff: adaptability on the left, precise page composition on the right.

What changes for the reader?

Question	Reflowable EPUB	Fixed-layout EPUB
Text size	Reader can usually resize it	Page is scaled as one canvas
Screen sizes	Text and images reflow	Composition stays fixed and may letterbox
Best for	Novels and text-led nonfiction	Picture books, comics and designed pages
Accessibility	Usually easier to support	Requires extra care and may limit controls
Maintenance	Styles can apply across chapters	Each page may need individual QA

Use reflowable EPUB when content order matters more than coordinates

If a paragraph can move below an image without changing meaning, reflowable is normally the stronger choice. Readers gain font size, line spacing and margin controls. Search, text selection and assistive technology also have a clearer document structure to work with.

Use fixed layout when coordinates carry meaning

A speech bubble, map label, worksheet field or caption positioned over an illustration may lose meaning if it moves. Fixed layout preserves that relationship. The cost is that small screens may shrink the entire page, so text must remain legible or have an appropriate magnification experience.

Do not convert by flipping the layout flag

A reflowable chapter does not become a designed page when you add pre-paginated. You must define page dimensions, rebuild styles for a fixed canvas and test each page. Similarly, removing the flag from an image-based fixed-layout book will not produce semantic paragraphs.

Ask these questions before choosing

Does the meaning depend on exact text-to-image placement?
Can the smallest important text be read when the full page fits a phone?
Is selectable text required?
Must screen readers follow headings, paragraphs and lists?
Can you test every page on multiple aspect ratios?
Will the book be sold through KDP, shared as a personal document or distributed to several reading systems?

Choose the format before production

Late conversion is expensive because the two formats express different reading models. Keep semantic source text even when producing a fixed-layout edition, and consider a separate reflowable edition when accessibility or small-screen reading would otherwise suffer.

Already have a fixed-layout file?

Use the repair and validation guides to distinguish package errors from problems that require returning to the original page design.

Open the repair guide →