Reflowable or fixed layout?

Novels, memoirs and most nonfiction should be reflowable: text rewraps to the screen and the reader's chosen font size. Picture books, comics, cookbooks with complex layouts and some textbooks need fixed layout, where every page keeps its design. Reflowable is more accessible and works everywhere; fixed layout is a deliberate exception.

Build with styles, not spacing

Whatever tool you use — Vellum, Atticus, Kindle Create, Sigil, Word or InDesign — ebook quality depends on clean structure:

  • Use real heading styles for chapter titles so the table of contents builds itself.
  • Use paragraph styles for first-line indents; never tabs or spaces.
  • Insert page breaks before chapters, not stacks of empty lines.
  • Use proper italics, not underline, and real quotation marks and dashes.
  • Avoid fixed font sizes and colours on body text — let the reader choose.

Images

Insert images at a sensible size (around 1600–2000 px on the long edge for full-width photos), compressed as JPEG for photos and PNG for line art. Add alternative text describing each meaningful image for screen-reader users. Avoid text inside images, which cannot reflow or be read aloud.

Every ebook needs a navigation table of contents (the menu readers use to jump to chapters). Fill in the metadata — title, author, language, publisher, ISBN if you use one, and description — because stores and library apps read it. In EPUB 3, add accessibility metadata describing what the book supports.

Front and back matter for ebooks

Keep front matter short so previews show your story or argument. Move acknowledgments, "also by" lists and newsletter invitations to the back, with working links. A link to the next book in a series is one of the most effective marketing pages you can include.

Test before you upload

  1. Validate EPUB files with EPUBCheck.
  2. Preview on several devices: a phone, a tablet, an e-ink reader, and Kindle Previewer for Amazon.
  3. Try large font sizes and dark mode — hard-coded colours and sizes break here first.
  4. Click every link in the table of contents and notes.

Which file for which store

EPUB 3 is accepted by nearly every retailer and library aggregator, and Amazon KDP converts EPUB uploads for Kindle. KDP no longer accepts MOBI for reflowable ebooks. See all ebook formats compared.