You get three Amazon categories per format (ebook, paperback, and hardcover each have their own three), chosen directly in your KDP dashboard, and the core principle is depth over breadth: a narrow, specific category with a few hundred competing books gives you a real shot at visibility, while a broad category with tens of thousands buries you. Categories decide which bestseller lists and browse pages your book can appear on, which makes them one of the more consequential, and most under-thought, decisions in self-publishing.
This is part of the Complete Guide to Amazon KDP Keywords and Categories.
Note: Amazon previously allowed authors to request up to ten categories by emailing KDP support; that option was removed in 2023. Three per format, self-selected in the dashboard, is the current system. Confirm this is still accurate before publishing, since Amazon's category rules have changed before and could change again.
Categories and keywords do different jobs. Backend keywords feed Amazon's search engine, determining which specific search queries your book can surface for. Categories determine which browse pages and bestseller lists your book appears on, the shelves it sits on, in effect. Both influence discoverability, but they work through different mechanisms. See Backend Keywords vs. Title, Subtitle, and Description Keywords for how the two relate.
A broad category like general "Fiction" or "Romance" might contain hundreds of thousands of titles, which means your book is competing against an enormous field for any meaningful visibility or bestseller ranking. A deep, specific subcategory, something like a particular romance subgenre or a specific mystery niche, might contain only a few hundred or a few thousand titles. Ranking within the top 100 of a narrow category is achievable in a way that ranking in the top 100 of a massive general category simply isn't for most books, especially early on.
Remember that ebook, paperback, and hardcover editions of the same book each get their own three categories. This means you can choose different categories for different formats if that makes sense for your book, though many authors keep them consistent for simplicity unless there's a specific reason to vary them.
Some authors choose categories purely to chase an Amazon bestseller badge in an extremely narrow, low-traffic category, one with so little competition that any small sales bump earns the tag. This can provide a temporary marketing talking point, but it does little for genuine discoverability if the category doesn't actually contain readers likely to buy your specific book. Balance the appeal of an achievable ranking against whether the category will actually connect you with real readers.
Categories, like keywords, can be changed at any time through your KDP dashboard. If a category isn't producing the visibility or sales you expected after a reasonable window, it's worth reconsidering, the same way you'd revisit underperforming keywords. See How Often Should You Update Your Book's Keywords and Categories?
Need Help With Your Book's Categories?
Entrada Publishing can help you think through category selection as part of getting your book ready to publish.
Three per format. Ebook, paperback, and hardcover editions of the same book each get their own three category selections.
Narrow, specific categories generally give you a better shot at real visibility and ranking than broad ones, as long as the category still genuinely describes your book.
You can, but it's worth weighing against whether the category actually connects you with readers likely to buy your book. A badge in an irrelevant category provides limited lasting value.
Yes, at any time through your KDP dashboard. Many authors revisit categories, like keywords, once they have real performance data to inform the decision.