The keywords field inside a KDP listing looks like a small box, but it is one of the more direct ways a book gets discovered by readers who are actively searching for something like it. Choosing well means thinking like the reader who is searching, not like a marketer trying to game a system.
This guide sets out a practical approach to choosing keyword phrases, grounded in reader language and KDP’s current field structure, while flagging the kinds of shortcuts that tend to backfire.
What keywords actually do
Keywords help Amazon’s search and recommendation systems understand what your book is about and match it to the terms readers type into the search bar. Unlike categories, which place the book in a browse structure, keywords are primarily about matching search intent to your book’s listing.
Because they work behind the scenes rather than being visible to readers directly, it is tempting to treat them as a place to stuff popular unrelated terms. This tends to be counterproductive: matching a search that has nothing to do with your book brings the wrong readers to the listing, which rarely converts and can produce negative signals over time.
Thinking in reader language
Start by imagining the actual reader who would love your book, and think about the words they would genuinely type into a search bar while looking for something like it. A reader is more likely to search "cosy mystery small town bakery" than a formal descriptive term you might use in a synopsis. Reader language is often more specific and more colloquial than an author’s own description of the book.
Genre-specific terms
Genre-specific phrasing that goes beyond the category name itself — for example a particular trope, sub-genre convention or reader shorthand common within a genre community — can be a productive keyword source, provided it is accurate to what the book delivers.
Themes as keyword sources
Central themes — grief, found family, second chances, coming of age — are often exactly what a reader searches for when browsing by mood or subject rather than strict genre. If your book explores a theme distinctly, a phrase reflecting that theme, used honestly, can help the right reader find it.
Setting-based keywords
For fiction with a distinctive setting — a particular era, region, or type of place — setting-based keyword phrases can help readers who specifically search by setting, such as those looking for books set in a particular historical period or location.
Audience-based keywords
Thinking about who the book is for, beyond genre, can surface useful phrases — for example a specific age range, life stage, or reader interest that the book genuinely speaks to. This is particularly relevant for non-fiction and children’s books, where audience is often as important a search dimension as subject.
Non-fiction: the problem the book solves
Non-fiction readers frequently search by the problem or question they want answered, rather than by genre. A book about negotiating a pay rise might be found by someone searching a specific phrase describing that exact goal. Thinking through the practical questions your book answers, in plain reader language, is often more productive than abstract subject description.
Long-tail phrases
Longer, more specific phrases (sometimes called long-tail keywords) can be valuable because they match more precisely to what a genuinely interested reader is looking for, even though fewer people search each individual specific phrase. A specific, accurate long-tail phrase describing your book’s niche is often more useful than a broad generic term with far more unrelated competition.
Categories vs keywords, again
It is worth repeating: categories and keywords are different tools serving different purposes. See our companion guide on choosing Amazon book categories for how the two should work together rather than duplicate one another. Using the keyword field to restate your category, rather than adding genuinely new search terms, wastes an opportunity to reach additional readers.
What not to use
Avoid keywords that misrepresent the book’s content purely to catch unrelated search traffic, and avoid anything that could resemble another author’s name, a trademarked term, or a well-known series or brand name you have no legitimate connection to. Check KDP’s current keyword guidelines directly, since Amazon periodically updates and enforces restrictions on this kind of content.
Repetition and redundancy
Repeating the same word across multiple keyword phrases, or restating words already present in your title or subtitle, tends to waste the limited space in the keyword field. Each phrase is generally more useful when it introduces a genuinely new angle a reader might search, rather than a minor variation of one already covered.
Avoiding trademark and competitor issues
Beyond the direct prohibition on using others’ names or trademarks, it is worth thinking about the reader experience: someone searching for a specific well-known author or series who lands unexpectedly on an unrelated book is unlikely to be a satisfied customer, regardless of whether the keyword technically drove a click.
Testing and reviewing keywords
Keywords can generally be edited after publication through the KDP dashboard, so treat your initial choices as a considered first attempt rather than final. If a book’s sales or search visibility seem weaker than comparable titles, revisiting the keyword list, alongside title, description and categories, is a reasonable diagnostic step.
Example
For example, an author of a business book might initially choose broad terms like "leadership" and "management," then later add a more specific phrase describing the exact problem the book solves, after noticing that comparable successful books used more specific reader-facing language.
Keeping metadata consistent
Keywords work best as part of a coherent whole with your title, subtitle, description and categories. If all of these consistently describe the same book to the same audience, Amazon’s systems and readers get a clear, trustworthy signal, which tends to matter more for genuine discoverability than any single clever keyword.
Changes over time
KDP’s keyword field structure, character limits and content rules are exactly the kind of detail that has been adjusted by Amazon over time. Always verify current requirements and restrictions directly on KDP’s help pages before finalising a keyword list, rather than relying on older guidance, including this one, without checking.
Common mistakes
- Stuffing unrelated popular terms into the keyword field. Matching unrelated searches brings the wrong readers to a listing, which rarely converts and wastes limited keyword space.
- Repeating words already in the title or category. Each keyword slot is more useful when it introduces a genuinely new search angle rather than restating existing metadata.
- Using another author’s name or a trademark as a keyword. This generally breaches Amazon’s current content guidelines and risks listing issues, beyond being unhelpful to readers.
- Treating keywords and categories as interchangeable. They serve different purposes; using keywords purely to restate a category wastes an opportunity to reach more readers.
- Never revisiting keywords after publication. Keywords can generally be edited later; treat the first list as a considered attempt, not a permanent decision.
- Guessing at reader language instead of researching it. Looking at how comparable books are described and searched for tends to produce better keyword choices than assumption alone.
Frequently asked questions
How many keywords can I add on KDP?
KDP provides a specific number of keyword fields with character limits that have been adjusted over time; check KDP’s current keyword help page for the exact current structure.
Can I use a competitor’s book title as a keyword?
Using another author’s name, series title or trademark to divert search traffic is generally against Amazon’s current content guidelines. Check KDP’s current policy before including anything like this.
Do keywords affect my category ranking?
Keywords primarily affect search matching rather than category browse placement; categories and keywords are separate tools with separate effects.
Can I change my keywords after the book is published?
Generally yes, through the KDP dashboard, though always confirm the current process on KDP’s help pages.
Should fiction and non-fiction keyword strategy differ?
Yes to some extent: fiction keywords often lean on genre, theme and setting language, while non-fiction keywords often work better reflecting the specific problem or question the book answers.