Amazon KDP keywords are seven short phrases you enter during book setup. They sit in a field most authors treat as an afterthought. That’s a mistake, because Amazon KDP keywords are one of the primary ways the algorithm decides which searches to show your book in. Get them wrong and you’re invisible to the readers who would actually buy it. Get them right and your book appears in front of people who are already looking for exactly what you wrote.
This is how to choose Amazon KDP keywords that actually work.
How Amazon KDP Keywords Actually Work
When someone searches on Amazon, the platform matches their query against a combination of signals: your title, subtitle, description, categories, and keyword fields. The keyword fields are your chance to capture searches that your title alone won’t cover.
Amazon gives you seven keyword fields with up to 50 characters each, so that’s 350 characters total to tell the algorithm where to show your book. Most authors waste this space on single words, romance, thriller, guide, that are either too broad to win or already captured by their title. Consequently, the smarter approach is phrases: the specific three-to-five word combinations real readers type when they’re in buying mode. They already know what they want. They’re just looking for the right book.
One important thing Amazon’s own guidelines confirm: do not repeat words already in your title, subtitle, or author name, since Amazon’s algorithm already indexes those. Keywords are for additional reach, not repetition.
Worth knowing for 2026 specifically: Amazon’s search stack is no longer just the classic A9 algorithm matching exact keyword strings. Since 2024, Amazon has layered COSMO, a semantic, knowledge-graph layer, on top of A9, and expanded Rufus, its conversational AI shopping assistant, through 2026. Rufus answers natural-language questions like “what’s a good fantasy series for fans of Brandon Sanderson?” by combining your keywords, description, reviews, and category signals together. As a result, single-word keyword stuffing carries even less weight than it used to. Descriptive, multi-concept phrases, the kind a real reader would actually type or say out loud, are what these systems are built to match.
The Difference Between Good and Bad Amazon KDP Keywords
Bad keywords are single words. “Thriller.” “Romance.” “Business.” These are so competitive and broad that you’ll never rank for them, and they tell Amazon almost nothing about the specific reader you’re trying to reach.
Good keywords are phrases that reflect how real people search. “Small town cozy mystery with recipes.” “How to self-publish on Amazon step by step.” “Military thriller series reading order.” These are the strings people actually type when they’re in buying mode. Therefore, the best Amazon KDP keywords are specific enough to reflect actual intent, relevant to your book, and active enough to be worth targeting.
Seven Types of Keyword Phrases Worth Using
Comparable Author Names
Readers often search for authors, then browse their work. If your thriller reads like Lee Child, a phrase like “books like Lee Child” or “Jack Reacher style thriller” puts you in front of readers who are explicitly searching for that experience. However, don’t put the author’s name alone, since you’ll never outrank their own page. Phrase it as a search query a reader would actually type.
Setting or Location Phrases
Readers who love specific settings search for them. “Scottish highlands mystery.” “New York City detective novel.” “Civil War historical romance.” If your book has a strong, distinctive setting, this is territory with lower competition than broad genre terms.
Character Type Phrases
“Female detective thriller.” “Disabled protagonist romance.” “Single dad love story.” Readers with specific preferences search exactly like this. These get overlooked because authors don’t think of their protagonist as a selling point, but readers absolutely do.
Mood and Tone Phrases
“Dark and twisty psychological thriller.” “Heartwarming small-town romance.” “Laugh-out-loud romantic comedy.” Mood is something readers search for, especially when browsing rather than looking for a specific title. Matching the mood to your actual book is critical, since a reader who expects heartwarming and gets dark will leave an unhappy review.
Problem or Outcome Phrases — Non-Fiction
For non-fiction, readers search for what they want to accomplish. “How to write a novel for beginners.” “First time home buyer guide.” “Anxiety management techniques for adults.” These are direct searches with high buyer intent, because the reader already knows they have a problem and wants a solution.
Time Period or Era Phrases
“Regency era romance.” “1970s coming of age story.” “World War Two resistance fighter fiction.” Historical specificity gets searched precisely, and these phrases capture readers who know exactly what period they want.
Trope Phrases
Romance readers in particular search by trope. “Enemies to lovers romance.” “Forced proximity small town.” “Second chance love story.” These phrases have active search communities behind them, so they signal immediately to the right reader whether your book is what they’re looking for.
How to Allocate Your Seven Amazon KDP Keyword Boxes
Knowing what kind of phrases to use is only half the job. Where you put them matters too, and here’s a practical way to split the seven boxes.
The first two boxes should hold your core genre and subgenre terms. Broad, but still essential, since they anchor what kind of book this is.
For boxes three through five, use your most specific, highest-intent phrases. This is where comparable authors, settings, character types, moods, and tropes go, because these are the phrases doing the actual discovery work.
Finally, the last two boxes work well for category-anchoring terms. Some keywords double as access points into Amazon’s narrower “tick categories,” sidebar subcategories that aren’t directly selectable during setup but unlock when a qualifying keyword is present. For example, including “shifter” in a paranormal romance can place your book into the Romance > Paranormal > Shapeshifter subcategory, on top of whatever search-query indexing that word earns you. One slot, two benefits. Since the qualifying list changes over time, check Amazon’s current keyword help page before relying on a specific term to unlock a category.
How to Research Your Amazon KDP Keywords
Start with Amazon’s autocomplete. Type a phrase into Amazon’s search bar, not Google, and see what Amazon suggests, since those completions come from real search activity. “Historical romance” might autocomplete to “historical romance Scotland,” “historical romance Viking,” “historical romance regency ballroom.” That’s data you can use.
Work through your genre, your setting, your character types, your comparable authors, and your mood. Write down every phrase combination, then narrow to your seven strongest, the ones most specific to your book that you can realistically compete for.
If you want to go further, Publisher Rocket’s Reverse ASIN feature is worth knowing about specifically. You take the ASIN of a competitor’s book, or any book similar to yours, and it shows you every keyword phrase that book is indexed for on Amazon, along with estimated monthly search volume and a 1-100 competition score for each. Instead of guessing which phrases might work, you can see the exact terms already driving sales for books like yours, then pick the ones with workable competition for your own seven boxes.
Publisher Rocket and K-lytics both have free trials, and if you’re publishing seriously, they’re worth the investment. You can also check what competing titles in your genre and category do without any paid tool, since many authors include keyword phrases naturally in their book description, and that tells you what’s working for similar books.
What Not to Do With Amazon KDP Keywords
Don’t use keywords that don’t describe your book, because Amazon will show your book to the wrong readers. Wrong readers buy it, feel misled, and leave negative reviews. A targeted keyword reaching fewer people but the right people beats a broad keyword that sells to nobody every time.
Don’t repeat words from your title, and don’t use keywords that violate Amazon’s guidelines, such as competitor author names used deceptively, trademarked terms, or anything suggesting rankings like “bestselling” or “award-winning.”
Finally, don’t set your keywords once and forget them. You can update them any time from your KDP Bookshelf, so if your book isn’t getting traction, testing new keyword phrases is one of the fastest things to try.
Categories and Keywords Work Together
Your KDP categories and your Amazon KDP keywords aren’t separate decisions, they’re two parts of the same discoverability system. Categories determine where your book appears in Amazon’s browse structure, while keywords determine where you appear in search. Strong category placement combined with accurate keyword phrases gives you both browse and search discovery simultaneously.
For a deeper look at the full KDP setup, read our guide on KDP vs IngramSpark and our step-by-step overview of how to get your book on Amazon. If you’d rather have a professional team handle the full setup, XpressPublisher covers distribution setup as part of our publishing services.
Frequently Asked Questions — Amazon KDP Keywords
How many keywords can I use on Amazon KDP?
Amazon KDP gives you seven keyword fields, each up to 50 characters. Phrases are almost always more effective than single words because they target specific search intent rather than broad generic categories.
Should I use my book title as a KDP keyword?
No. Amazon already indexes your title, subtitle, and author name, so use your keyword slots to capture search phrases your title doesn’t already cover.
Can I use other authors’ names as KDP keywords?
It’s a grey area. Phrases like “books similar to [Author Name]” are commonly used and not explicitly prohibited. However, Amazon’s policy updates regularly, so check current guidelines before using competitor names.
How often should I update my Amazon KDP keywords?
Review them when your book isn’t selling as expected, when you launch a new edition, or when genre trends shift. You can update at any time from KDP Bookshelf without republishing your files.
What’s the best tool for finding Amazon KDP keywords?
Publisher Rocket is the most widely recommended paid tool for KDP keyword research, particularly its Reverse ASIN feature for seeing competitor keyword data directly. Amazon’s own autocomplete is a free starting point, so type your genre phrases directly into Amazon search, not Google.
What is the Reverse ASIN technique for Amazon KDP keywords?
Reverse ASIN is a Publisher Rocket feature where you enter the ASIN of a competitor or comparable book and it returns every keyword phrase that book is indexed for, along with estimated search volume and a competition score. It’s the fastest way to find proven keyword phrases without guessing, since the phrases are already driving discovery for books similar to yours.