Which file to upload
KDP's supported-formats page lists KPF as the recommended file, because it lets the eBook format and fit all Kindle devices; DOC and DOCX, most of which convert well; and EPUB that meets the specifications in the Kindle Publishing Guidelines. HTML, RTF and TXT are accepted too. Two cautions on the same page: effective March 2025, MOBI files are no longer accepted for fixed-layout eBooks, and PDF is supported only in a listed set of languages (English, French, German, Italian, Portuguese, Spanish, Catalan, Galician and Basque). For a text book the practical choice is EPUB or DOCX; the studio exports both.
Formatting that survives conversion
Reflowable means the reader's device decides the line breaks, the page breaks and the type size. Anything you force will fight it. Use real heading styles for chapter titles and section heads, real paragraph styles for body text, and a real table of contents built from those headings — Kindle builds its navigation from them. Do not indent with spaces, do not add blank lines for spacing, do not paste in text boxes, and keep images small and few, because file size raises the delivery cost on the 70% royalty option. A chapter should start on a new page; a page break before each chapter heading does that.
Checking the file before upload
Two checks catch most problems. Validate the EPUB: an EPUB that passes epubcheck opens everywhere and converts without surprises, and the studio's EPUB export is built to pass it. Then preview: KDP's own previewer shows the book as it will render on a Kindle, a tablet and a phone. Read the first chapter on the phone view — that is the size most readers use — and look for headings that lost their style, lists that became paragraphs, and the table of contents pointing to the right places. Fix in the source file, re-export, re-upload; do not patch the converted file.
Common questions
Straight answers
Do I need Kindle Create?+
No. It produces the recommended KPF file and is free, but a clean EPUB or DOCX converts well. Use it if you want KDP's own layout templates.
Should chapters have page numbers?+
Not in a reflowable eBook — there are no fixed pages. Page numbers belong in the PDF and print editions; the EPUB uses the navigation document instead.
Sources
Platform figures on this page are quoted from the pages below, read on the date shown. Rules change; check the current page before you publish.
Amazon KDP — Supported eBook Formats · read 2026-09-11
Amazon KDP — Digital Book Pricing Page (delivery costs) · read 2026-09-11
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