KDP keywords: how to fill the seven slots

When you set up a book on Kindle Direct Publishing, the details page gives you seven boxes labeled keywords. Readers never see them. Amazon uses them, along with the rest of your metadata, to decide which searches your book can appear in. Seven short fields don’t sound like much, but they’re one of the few parts of a listing that exist only to help readers find you.

This guide covers how the slots work, what Amazon tells you to avoid, and a repeatable way to fill them.

How the seven slots work

KDP asks for up to seven keywords or short phrases per format. Your ebook and paperback are set up separately, so each format has its own seven boxes, and you can change them at any time from your Bookshelf.

Each box has a character limit, which the form enforces as you type (50 characters at the time of writing). Because the limit applies to the box rather than to a single phrase, a box can hold one longer phrase or two or three closely related terms.

A few points cause most of the confusion:

• Word order matters. Write phrases in the order a reader would type them: “military science fiction,” not “fiction science military.”
• Repetition doesn’t add weight. Using “mystery” in four boxes doesn’t make the book more relevant for “mystery.” It just uses up space you could spend on other phrases.
• Your title already counts. Amazon tells you not to repeat information that’s already in other metadata, such as the title or contributor names.

What Amazon says to avoid

KDP’s keyword guidance lists things that don’t belong in the boxes. In plain terms:

• Words already in your title, contributor names, or chosen categories
• Subjective claims such as “best” or “must-read”
• Time-sensitive words such as “new” or “on sale”
• Words common to almost every book, such as “book” or “novel”
• Misspellings, and spacing, capitalization, or plural variants of the same word
• Names of other authors, books, or brands you aren’t connected to
• Amazon program names such as “Kindle Unlimited” or “KDP Select”
• Quotation marks and HTML

Some of these are about wasted space; others are about policy. KDP says it has zero tolerance for metadata meant to mislead, and putting a bestselling author’s name in your keywords is the classic example.

What makes a good keyword

KDP suggests thinking in the terms readers search by. For fiction, those include:

• Setting: “Victorian London,” “small coastal town,” “space station”
• Character types: “single dad,” “retired detective,” “witch”
• Character roles: “strong female lead,” “reluctant hero”
• Plot themes: “second chance,” “found family,” “revenge”
• Tone: “feel-good,” “dark,” “funny”

For nonfiction, think about the reader’s problem, the outcome they want, the method, and who they are: “budget meal prep for families,” “strength training over 50,” “small business bookkeeping.”

The best keywords are specific enough that the books ranking for them look like yours, and common enough that real readers type them.

A method for filling the slots

1. Describe the book the way a reader would

Write ten to twenty phrases a reader might use to describe your book to a friend. Avoid industry terms unless readers use them too. A reader is more likely to search for “cozy mystery with recipes” than “culinary amateur sleuth fiction.”

2. Check what Amazon suggests

Open Amazon in a private browser window, choose the Kindle Store or the Books department, and start typing each phrase. The autocomplete suggestions show what shoppers commonly search for. Note the suggestions that fit your book, including longer versions of your phrases.

3. Check the results page

Search for each candidate and look at the first page of results. Ask two questions:

• Do these books look like mine? Similar covers, subgenre, and audience mean the phrase brings in the right readers.
• Is there room? If every result is a household-name bestseller, a narrower phrase may serve you better.

A phrase that returns unrelated books is a mismatch, however popular it is.

4. Group and fill

Group related phrases and fill each box with a phrase or a cluster that reads naturally. Put your most important, most specific phrases first. Don’t repeat words across boxes unless a phrase can’t work without them.

5. Record and revisit

Keep a dated note of what you used. After launch, check whether your book shows up for your main phrases. If a phrase isn’t working, replace it, but change a few at a time so you can tell what made a difference.

An example

Here’s how the slots might look for a hypothetical historical romance about a widowed rancher in 1880s Montana:

1. historical western romance widowed rancher
2. montana frontier love story 1880s
3. second chance clean and wholesome
4. marriage of convenience cowboy
5. found family ranch life
6. brave heroine homestead
7. slow burn sweet heartwarming

Notice what’s missing: the title, “book,” “novel,” “best,” other authors’ names, and any category words already selected. Each line also stays under the character limit.

Common keyword mistakes

• Single broad words. “Romance” or “fantasy” on its own puts you in competition with every book in the genre. A specific phrase gives readers who want your kind of book a way to find it.
• Commas and stuffing. Lists of words separated by commas waste characters and don’t read like a search. Write phrases.
• Copying the paperback from the ebook without checking. The Books department and the Kindle Store return different results. Check your phrases in both.
• Describing the wrong audience. Words like “kids” or “teen” in the keywords of an adult book bring in readers who will be disappointed, and the reverse can cause real problems for parents.
• Borrowing competitors’ terms that don’t fit. A phrase that works for a comparable book only works for yours if it describes your book, too.
• Setting and forgetting. Search habits and your own understanding of your readers change. A keyword review once or twice a year costs little.

Check whether a keyword is working

Changes can take a few days to show up in search, so wait before judging. Then, in a private browser window, search for each of your main phrases in the right department and see where your book appears. If it doesn’t appear for a phrase that describes it well, the phrase may be too competitive for a new book; try a longer, more specific version. If your book appears but the surrounding results look nothing like it, the phrase is drawing the wrong readers, even if it brings clicks.

If you run Amazon Ads, the search terms report shows the actual phrases shoppers typed before clicking your ads. It’s one of the best sources of new keyword ideas, because it reflects real searches rather than guesses.

Keywords, categories, and ads are different tools

Keywords help your book appear in search results. Categories place it on browse shelves and bestseller lists, and you choose those directly during setup. Older guides describe using keywords to get a book into specific categories; KDP now has you select categories directly, so keep the two jobs separate.

Amazon Ads also use keywords, but they’re a separate system with its own targeting. Ad keywords can be broader and more numerous, and they don’t change your seven backend slots.

Keyword checklist

• Seven boxes filled, each using the space without padding
• No words from the title, subtitle, author name, or categories
• No subjective, time-sensitive, or program terms
• Every phrase checked in Amazon search, with results that look like your book
• Ebook and paperback both filled in
• A dated record of what you used, to review after launch

AIBookWriter’s free KDP Keyword Research tool takes one seed phrase and suggests phrases for all seven slots. Use its suggestions as candidates, then run each one through the search checks above before you keep it.