2026-06-30 · all guides

KDP Keyword Research for Free: 5 Methods That Cost Nothing

Method 1: mine Amazon autocomplete like a database

The Amazon search bar is the most honest keyword tool in existence, because its suggestions are generated from real shopper queries weighted by volume. Set the search dropdown to the Kindle Store or Books, type your core topic, and record every completion. Then go systematic: type your topic followed by each letter of the alphabet, one at a time, and harvest the suggestions for each. Sourdough a, sourdough b, sourdough c will each surface different real queries.

Two refinements make this dramatically better. Use a private browser window so your own history does not contaminate suggestions. And run the alphabet drill on modifier patterns too: for beginners, without, how to, and audience words like for women or for kids each unlock a different branch of the suggestion tree. Thirty minutes of this produces 50 to 100 real queries, which is more raw material than seven slots can hold.

Method 2 and 3: competitor listings and category shelves

Your successful competitors have already done keyword research, and their conclusions are printed on their listings. Pull up the top ten books for your main search term and study their subtitles: every phrase in a bestselling subtitle is a phrase someone validated. Note the recurring words across listings, because convergence signals volume. Their bullet-heavy descriptions repeat the same vocabulary, and that repetition is a map of the language buyers respond to.

Category shelves add another layer. Browse the subcategories your competitors sit in and read the category names themselves; Amazon browse-tree labels like Budgeting and Money Management or Small Business Marketing are quality keyword phrases in their own right, since Amazon literally organized its store around them. Walking three levels of the category tree around your topic reliably surfaces phrases your brainstorm missed.

Method 4: read reviews for the words buyers actually use

Reviews on competing books are unfiltered buyer vocabulary. Read 20 to 30 reviews across your top competitors and highlight the nouns and phrases reviewers use to describe why they bought and what they wanted: finally explained meal prep for one person, needed something for my anxious teenager, wanted a guide without expensive equipment. These phrasings are search queries in embryo, and they routinely differ from the polished language on covers.

Negative reviews are even more valuable, because complaints reveal unmet demand you can both write toward and index for. If multiple reviews complain that a popular book skips a topic or assumes expensive gear, then phrases naming that gap belong in your keyword slots and your subtitle. You are not just harvesting words; you are finding the positioning the incumbent books left open.

Method 5: validate before you commit the slots

By now you have a long list; validation cuts it to the best 40-odd words. Search each candidate phrase in the Kindle Store and look at two things: how many results come back, and whether the first page is beatable. A phrase with a few thousand results and a first page of older, thinly reviewed books is a target. A phrase where page one is all heavyweight titles with thousands of reviews will not send you traffic even if you technically index for it.

Then pack the survivors into your seven 50-character slots, keeping the rules in mind: no words repeated from your title, no free, no bestseller, no competitor names. If you want a generated starting point to validate instead of a blank page, ebookdone produces seven keyword strings in the metadata pack that ships with every 9 dollar book at /new, and the validation loop above works the same on generated strings as on handwritten ones. Research is free; the discipline to actually do it is the whole edge.

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