EPUB vs PDF for KDP: Which File Format Should You Submit?

Here is a quick reference table showing which file format to submit based on your book format and publishing goals:

For print layouts, you must ensure your PDF meets specific standards. Read our guide on what is a print-ready PDF to avoid validation errors.

An EPUB file is required for Kindle eBooks and digital distribution. Because readers access eBooks on devices ranging from small phones to large tablets, the text must be reflowable. EPUB allows the user to customize their reading experience—changing font size, style, and contrast—while ensuring the content formats correctly without requiring horizontal scrolling.

A PDF is required whenever you are publishing print formats (paperback or hardcover) on KDP or IngramSpark. Print production relies on a fixed layout, meaning every page margin, page break, and font placement must remain identical to how the designer built it. PDF acts as a digital photograph of your page, ensuring the printer prints exactly what you designed.

Uploading a print-ready PDF to KDP for a Kindle eBook is a recipe for disaster. Because PDFs lock elements into fixed layouts, they do not reflow on screens. On a mobile phone, the print page scales down, making the text microscopic and unreadable. KDP's automatic conversion of PDFs often leaves titles, page headers, page numbers, and images completely scattered and out of order.

Conversely, you cannot upload an EPUB file for print publishing. Print layout requires millimeter-level control over margins, spine width, page counts, running headers, and footers. Because EPUB text flows dynamically, the page count changes depending on the viewer's screen settings, making it impossible for physical printing machines to determine where to cut pages or size the cover spine.