Reflowable vs fixed-layout ePUB: which does your book need?

If your book is mostly text — a novel, a memoir, most non-fiction — you want a reflowable ePUB, where the words rearrange to fit any screen, font and size the reader picks. If the page itself is the design — a picture book, cookbook or comic — you want a fixed-layout ePUB, which locks every page like a PDF.

What does reflowable actually mean?

A reflowable ePUB has no fixed pages. The text is a continuous stream, and the reading app pours it into whatever space it’s given — a phone in portrait, a tablet in landscape, a six-inch e-ink screen at a large font for tired eyes. The reader picks the typeface, the size, the line spacing, the background colour, and the book rearranges itself to suit while staying whole. As we put it in our ePUB production work, that flexibility is the entire reason eBooks exist.

It only works when the underlying structure is clean. Force the layout — fake line breaks, images jammed where text should flow, hard-coded spacing — and the file becomes fragile: fine at one size, shattered at another. A properly built reflowable file holds together at every size, on every device. That’s invisible craft, which is why people underestimate it.

What does fixed-layout mean, and when is it the only option?

A fixed-layout ePUB pins every element to an exact position on a page of exact dimensions, exactly as you designed it. Text and image stay locked together; nothing reflows. It is, in effect, a designed page delivered as an eBook — close in spirit to a PDF, but built to the ePUB 3 standard so stores and apps can read it.

You need it when the layout is inseparable from the content. The clear cases:

• Children’s picture books — words sit on the illustration, in a specific place, in a specific size. Reflow them and the book falls apart.
• Cookbooks — ingredient columns, step photos and method need to stay aligned on the page.
• Comics and graphic novels — the panel grid is the storytelling.
• Heavily designed non-fiction — art books, photography, illustrated guides, anything with sidebars, captions and image–text relationships that must hold.

If you’re not in one of those buckets, you almost certainly want reflowable. A novel does not benefit from fixed pages; it’s actively harmed by them, because the reader loses the font and size controls that make eBooks comfortable.

Factor	Reflowable ePUB	Fixed-layout ePUB
Best for	Novels, memoir, most non-fiction	Picture books, cookbooks, comics, design-heavy titles
How the page behaves	Text reflows to any screen and font size	Page is fixed, like a PDF
Reader controls	Full — font, size, spacing, theme	Limited — mostly zoom and pan
File size	Small (text-led)	Large (full-resolution images per page)
Device support	Universal, including small e-ink readers	Best on tablets and larger colour screens
Accessibility	Strong — resizable, screen-reader friendly	Weaker — depends on careful build
Store acceptance	Accepted everywhere as standard	Accepted, but with format-specific rules

How different are the file sizes?

Substantially. A reflowable novel is mostly text plus a cover, so the file is tiny — measured in kilobytes or a few megabytes. A fixed-layout book carries a full-resolution image for every page, so a picture book or cookbook can run to tens or even hundreds of megabytes. That matters for two reasons: some stores cap file size or charge a delivery fee scaled to it, and a heavy file is slower to download and harder on older devices. Fixed-layout is worth it when the images are the book — but it’s a real cost you’re choosing to pay.

Will both work on every device and store?

Reflowable is the universal currency. It reads correctly on Kindle, Kobo, Apple Books, Google Play Books and every other major app, on screens from a phone to a small e-ink reader, because the format is designed to adapt. Every store accepts it as the standard, and it’s what we build by default — every reflowable file we produce is validated against EPUBCheck, the same gate the stores themselves use.

Fixed-layout is accepted too, but with more conditions. Apple Books and Google Play handle ePUB 3 fixed-layout well; Kindle uses its own fixed-layout flavour, so a picture book bound for KDP needs a Kindle-targeted export rather than the same file you’d send to Apple. It also shows best on tablets and larger colour screens — a fixed page designed for a generous canvas is cramped and fiddly on a small e-ink device. None of this is a blocker; it just means a fixed-layout title is a different build with its own checks, not a switch you flip on a reflowable file.

What about accessibility?

This is reflowable’s quiet superpower. Because the text is real, resizable text rather than a picture of text, a reflowable ePUB works with screen readers, supports large-print and dysl-friendly fonts, respects high-contrast themes, and lets a low-vision reader simply turn the type up. Accessibility isn’t a nicety here — in much of Europe it’s increasingly a legal expectation for digital books, and reflowable gives it to you almost for free.

Fixed-layout has to work harder. Because the page is locked, accessibility depends on the build: proper alt text on every image, a sensible reading order, and real text wherever text can be real rather than baked into the artwork. It’s achievable, but it doesn’t come automatically — it’s a deliberate part of preparing the file well.

What if my book is somewhere in between?

Plenty of books are mostly text with a handful of images — a non-fiction title with a few charts, a memoir with a photo section. These stay reflowable. You don’t switch a whole book to fixed-layout for the sake of a dozen pictures; you place the images so they sit gracefully in the flow and let the text keep its flexibility. Fixed-layout is for when the design is load-bearing on nearly every page, not for the occasional figure.

If you genuinely can’t tell which camp you’re in, the deciding question is simple: does the reader need to see this page exactly as I designed it, or do they need to read these words comfortably on their own terms? Answer that honestly and the format chooses itself.

Do my print and eBook editions have to match?

They don’t have to be identical — print is fixed, a reflowable eBook flows — but they should feel like the same book. The sensible approach is to build them from one clean source so wording, structure and front matter stay consistent across formats. For an image-led title you might pair a fixed-layout eBook with the print edition; for a text-led one, a reflowable eBook beside the paperback. Either way, consistency is a production decision worth making on purpose. You can read more about that in our guides, and the underlying specs live in the book specs reference.

We build reflowable ePUB 3 by default — clean, EPUBCheck-validated and ready to upload to every store first time — and we take on fixed-layout titles as a separate, carefully built job when a picture book, cookbook or comic genuinely needs it. If you’re not sure which your book wants, tell us what you have and we’ll advise before you commit.