Kindle Publishing Requirements: What KDP Actually Needs From Your Ebook File
Amazon KDP is where most self-published ebooks land. Free to upload. Strong royalties. The biggest ebook marketplace in the world.
Also, and I say this from experience working with a lot of authors, a place where a lot of books get stuck because the file isn't quite right. Quality review rejection. Upload errors. Books that go live but look terrible because the automatic conversion didn't know what to do with the source file. I've seen all of it. So here's a no-nonsense guide to what Amazon KDP actually requires from your ebook, so you don't have to learn any of this the hard way.
Which File Format to Upload (And Why It Matters)
KDP accepts several formats. They're not equally good.
EPUB: Use This One
EPUB is the industry standard for a reason. A properly structured EPUB gives you the most control over the reading experience and produces the most consistent results across Kindle devices. Amazon converts uploaded EPUBs to its internal Kindle format during processing. If your EPUB is built correctly, the conversion is clean.
DOCX… Fine for Simple Books
Word files are accepted and are the easiest starting point for straightforward, text-heavy books. The trade-off: KDP's automatic conversion from DOCX can get inconsistent when formatting gets complex. For a novel with minimal formatting, DOCX is fine. For anything more complicated, EPUB gives you more control.
PDF: Generally Avoid This
Word files are accepted and are the easiest starting point for straightforward, text-heavy books. The trade-off: KDP's automatic conversion from DOCX can get inconsistent when formatting gets complex. For a novel with minimal formatting, DOCX is fine. For anything more complicated, EPUB gives you more control.
The Formatting Requirements That Actually Get Books Rejected
Table of Contents: Non-Negotiable
A functional, clickable table of contents is required for any ebook of meaningful length. Clickable is the key word not just a page that lists chapter names, but actual links that take the reader to that chapter. KDP checks for this. Readers notice immediately when it's missing or broken.
This is the single most common reason ebooks fail KDP quality review.
Heading Structure
Chapter titles and section headings need to be tagged with the correct heading levels H1, H2, H3 in the ebook's underlying code. A line that looks like a heading because it's big and bold is not the same as a line that is tagged as a heading. Reading devices use that structure to build navigation menus. Screen readers use it for accessibility. Get it wrong and you've got an ebook that looks amateur and behaves badly.
Paragraph Formatting
Amazon's guidelines are specific: body text should use either paragraph-style indentation (first-line indent) or block-style spacing (space between paragraphs). Not both. Inconsistent paragraph formatting the classic artifact of converting a print file without cleanup makes your ebook look like it was assembled by accident.
Hard Page Breaks in Body Text
Print books use hard page breaks to control exactly where chapters start and end. In a reflowable ebook, hard page breaks between paragraphs create blank screens in the middle of a chapter. Body text should flow continuously; page breaks only between chapters.
Paragraph Formatting
Amazon's guidelines are specific: body text should use either paragraph-style indentation (first-line indent) or block-style spacing (space between paragraphs). Not both. Inconsistent paragraph formatting the classic artifact of converting a print file without cleanup makes your ebook look like it was assembled by accident.
Cover Requirements (Uploaded Separately)
Your cover is a separate upload from your manuscript. The specs: minimum 1,000 pixels on the longest side, ideal size 2,560 x 1,600 pixels, aspect ratio approximately 1.6:1 (height to width), JPEG or TIFF under 50MB.
A cover that doesn't meet specs gets rejected at upload. A cover that technically meets specs but looks bad at thumbnail size which is how it appears in Amazon search results will hurt your sales more than any formatting issue. Your cover needs to be readable at the size of a postage stamp.
Metadata: The Part Authors Usually Rush
Title Matching
Your ebook title on KDP must match the title on your cover. Exactly. Discrepancies between the cover image and the metadata field can trigger quality review failures. Sounds minor. It's not.
Author Name
Pen names are fine. But the name you enter in KDP needs to match the name on your cover and title page, consistently.
ISBN
Not required for Kindle ebooks. Amazon assigns its own ASIN identifier. But if you're distributing the same ebook through Apple Books, Kobo, or Barnes & Noble, having your own ISBN keeps things consistent across retailers. (Need help getting ISBNs? We can assist!)
Categories and Keywords
KDP allows two categories and seven keywords. These directly affect discoverability on Amazon. Choose based on what readers actually search for, not what broadly describes your book. This is worth spending real time on.
Amazon's Content Quality System
Here's something not enough authors know: Amazon doesn't just review your book at upload. They monitor it after it's live, based on reader feedback.
Ebooks with consistent formatting complaints "formatting is terrible," "broken navigation," "text runs together" can be suppressed by Amazon. Removed from search results until the issues are corrected. By the time that happens, your launch momentum is gone.
Professional ebook conversion isn't just about passing the upload. It's about the ongoing health of your book's listing.
What About Kindle Create?
Amazon's free Kindle Create tool is genuinely useful for straightforward, text-heavy books. It produces KPF files that upload directly to KDP with predictable results.
The limitations: basic formatting options, a learning curve for authors unfamiliar with ebook production, and importantly it only produces Kindle format.
If you want to publish on Apple Books or Kobo too, you need EPUB. Kindle Create won't give you that.
How DiggyPOD Handles This
Our ebook conversion process produces files built to meet Amazon KDP's technical requirements and quality guidelines from the start. Structural formatting, navigation, metadata, image handling, multi-device testing. You receive EPUB and Kindle-ready files with upload guidance.
If your print book was produced by DiggyPOD, we start from your existing files. If you're bringing something in from elsewhere, we start with a file review so you know exactly what you're working with before the project begins.
FAQ’s
Does KDP accept PDF uploads for ebooks?
Yes, but it’s not recommended. PDF conversion on KDP produces inconsistent results. EPUB and DOCX give you better output for reflowable ebooks.
What's the best file format for Amazon Kindle?
A properly structured EPUB. Amazon converts it to Kindle format during processing. EPUB also works on every other major ebook platform, so you’re covered either way.
Do I need an ISBN for my Kindle ebook?
No. Amazon assigns its own ASIN. An ISBN is optional on Amazon but useful if you’re distributing through other retailers.
How long until my ebook is live on Amazon?
Amazon typically publishes within 24–72 hours of upload. Books that fail quality review are returned with notes on what needs to be fixed.