The 7 KDP keyword boxes: what actually works

By Tracy Atkins, founder of BookDesigner.ai and BookDesignTemplates.com · 15+ years of print files, 70,000+ authors · Updated July 20, 2026

The rules of the boxes

You get seven keyword fields, and each one holds up to 50 characters. That character budget is the single most important fact about the tool, because it tells you the fields are built for phrases, not words. A field that just says "romance" throws away more than forty characters of room you could have used to describe exactly what kind of romance you wrote.

So the first shift is to stop thinking "seven words" and start thinking "seven search phrases." Each phrase should be something you could imagine a reader actually typing into the Amazon search bar when they are hunting for a book like yours.

Phrases beat single words

Single words are almost always too broad to help. "Mystery" is competing with hundreds of thousands of titles, and your book will never surface for it. A phrase like "cozy small town murder mystery" is far more specific, far less crowded, and matches the intent of a reader who wants precisely that. Multi-word phrases also let your book appear for the shorter searches contained inside them, so a good phrase does double duty.

Do not repeat what you already own

Amazon already indexes the words in your title, subtitle, and category names. If your title contains the word "gardening," you do not need to spend a keyword field on "gardening" again, because you are already searchable for it. Repeating those terms in the keyword boxes is pure waste of a scarce resource. Treat the seven fields as the place for everything your title does not already say: tone, setting, theme, audience, the mood a reader is chasing.

Stay inside the policy line

Two things will get you in trouble. Using another author's name to ride their searches is against Amazon's policy, and so is using trademarked terms you do not own. It is tempting to drop in a famous name because you know your book appeals to their fans, but that is exactly the move Amazon polices. Describe your book on its own merits instead. If you want to signal "readers of a certain famous author will like this," that belongs in your comparable-titles research and ad targeting, not in the keyword fields.

Reader language, not writer language

Writers describe their books the way a review would. Readers search the way they talk. The phrase "contemporary literary romance novel" is how an author thinks about their book. "Small town romance second chance" is how a reader looks for one. The reader phrase wins, because it matches the words people actually type. Before you finalize any field, ask whether a shopper who has never heard of you would ever type it. If not, rewrite it in plain reader language.

Keywords quietly set your categories

Keywords are not only about search. Amazon also uses them to help decide which categories your book belongs in. Well-chosen phrases can qualify your book for additional, tightly matched shelves, while vague or off-genre phrases can nudge it toward shelves you did not want. This is one more reason your keywords, categories, and description all have to tell the same story about your book.

A worked example

Say you wrote a warm second-chance romance set in a coastal town, aimed at readers who like emotional, low-heat stories. Your title and subtitle already carry the author name and the words "romance" and "harbor." Here is how the seven fields might fill out, each a reader-style phrase and none repeating the title.

Every field is a phrase, every one is in reader language, none repeats the title, and none uses another author's name. Together they describe the book from several angles a shopper might search from.

Test, because it is free

You can change your keywords at any time at no cost, and the change simply goes through Amazon's review before it takes effect. That makes keywords the cheapest experiment in your whole listing. Fill the seven fields thoughtfully, give them a few weeks, and if a phrase never seems to earn its place, swap it for something narrower. There is no penalty for iterating, so treat the boxes as a living part of your listing rather than a decision you make once and forget.

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