Amazon Keyword Research for Books

Banned keyword terms: Amazon prohibits superlatives (best, top, #1), promotional language (sale, cheap, discount), your title's own words, bare category names (romance, thriller), and competitor author or brand names. Violations get keyword slots stripped silently — the listing stays up but loses those discovery signals.

Search

Go to Amazon's book search. Type your genre + a space + a letter.

Record

Note every autocomplete suggestion. Each is a phrase real readers typed enough times for Amazon to surface it.

Repeat

Go through a–z for your primary genre. Add your main sub-genre and repeat. Takes 20–30 minutes but produces validated phrases.

Filter

Remove phrases that don't describe your specific book. Keep the ones that match your setting, trope, tone, and audience.

Format

Trim each phrase to under 50 characters. Remove words that duplicate your title. Prioritize specificity over breadth.

1. Log in to KDP and open your book

Go to kdp.amazon.com → Bookshelf. Find your title and click the three-dot menu → Edit book details. For a new book, start at the beginning of the publishing flow.

2. Navigate to Keywords section

In the book details page, scroll to the Keywords section. KDP shows 7 numbered fields labeled "Keyword 1" through "Keyword 7." Each field accepts up to 50 characters.

3. Enter one phrase per field

Paste one complete keyword phrase into each field — not a comma-separated list. "cozy mystery bakery small town" is one field entry. Amazon treats each field as a complete phrase for matching purposes.

4. Check character counts

Each field has a 50-character limit. KDP shows a character counter as you type. Use all available characters — a 48-character specific phrase outperforms a 12-character generic term in the same slot.

5. Save and republish

Click Save and Continue. If the book is already published, keyword changes go live after KDP processes the update — typically within 24–72 hours. Changes don't require a new review cycle for most edits.

Ghost categories — how to get into them

KDP's standard category picker shows a subset of Amazon's actual browse tree. Ghost categories exist in the public tree — you can find books listed in them — but don't appear in the publisher interface. To get added:

1. Publish your book first — you need an ASIN.
2. Email KDP support with your book's ASIN and the exact category path (e.g. "Kindle Store > Kindle eBooks > Literature & Fiction > Genre Fiction > Horror > Occult").
3. KDP support adds the category manually — typically within 1–3 business days.
4. You can request up to 10 total categories (2 selected at upload + up to 8 added via support).

How many keyword slots does Amazon KDP give you?

KDP gives you 7 keyword fields, each up to 50 characters including spaces. Every slot should contain a complete keyword phrase — not a list of comma-separated single words. Amazon indexes phrases as phrases, so "cozy mystery recipes small town" is one targeted phrase that matches a specific reader query. Seven separate single words like "cozy,mystery,recipes,small,town" give you seven generic signals that compete against everything in those categories.

Should I repeat keywords that are already in my title?

No. Amazon automatically indexes your title, subtitle, series name, and author name. Adding words from your title to the backend keyword slots wastes space. Use keyword slots for angles your title doesn't already cover — different subgenres, tropes, settings, or audience descriptors that connect your book to reader queries Amazon wouldn't otherwise know to match.

What keywords are banned on Amazon KDP?

Amazon prohibits: superlatives (best, top, greatest, #1), promotional language (sale, cheap, discount, free), words already in your title, category names used as keywords ("thriller," "romance"), and competitor author or brand names. Violations result in keywords being stripped silently or the listing being flagged. Use complete descriptive phrases rather than category labels.

What are the most searched keywords on Amazon for books?

Amazon doesn't publish search volume data publicly, but its autocomplete function reveals the phrases real readers type most often. For fiction, high-volume patterns include romance subgenre + trope phrases ("small town romance second chance"), fantasy setting + magic system phrases ("dark academy magic enemies to lovers"), and thriller type + mood phrases ("psychological thriller unreliable narrator"). For nonfiction, problem + audience phrases dominate ("anxiety relief workbook adults," "budget meal prep beginners"). The common thread: readers search for the reading experience or the outcome, not the book's subject matter.

How often should I update my KDP keywords?

Review every 60–90 days, or sooner if organic traffic drops noticeably. Amazon's algorithm evolves, reader search language shifts with trends, and new competing titles change the competitive landscape for specific phrases. Run fresh research before updating — don't replace working keywords with untested ones. Changing keywords resets some algorithmic signals, so make targeted changes rather than replacing all 7 at once.

What's the difference between KDP backend keywords and category keywords?

Backend keyword slots and category selection are separate inputs that work together. Your 7 keyword slots influence which Amazon searches surface your book. Your categories determine which browse menus it appears in and which bestseller lists it's eligible for. Some categories are only accessible by requesting them through KDP support after publishing — these "ghost categories" don't appear in the standard picker. Using category-relevant phrases in your keyword slots can reinforce browse placement beyond the 2 categories you select at upload.

Does Amazon use keyword slots for advertising?

Backend keywords influence organic discovery, not ad targeting directly. Amazon Ads uses separate keyword targeting that you set within the ad campaign. That said, the research process overlaps — the same phrases that match organic reader searches are often the right starting point for Sponsored Products keyword targeting. Authors who've done thorough backend keyword research typically start ad campaigns with a stronger keyword list.

Is there a difference between fiction and nonfiction keyword strategy?

Yes — significantly. Fiction readers search for the reading experience: trope, setting, sub-genre, and emotional tone. Nonfiction readers search for the problem they want solved and the outcome they want to achieve. A thriller author using nonfiction-style problem phrases ("how to survive a thriller") or a nonfiction author using fiction-style trope phrases will miss their actual reader. The keyword research approach and the phrase structures that work are different for each.

How do I check if Amazon has indexed my KDP keywords?

Search Amazon for the exact keyword phrase you submitted — type it into Amazon's book search bar. If your book appears in results, the keyword is indexed. If it doesn't appear, either the keyword hasn't propagated yet (allow 24–72 hours after publishing or updating), or Amazon didn't index that phrase. Narrow the search by adding your author name or a distinctive title word to confirm your book's rank for that phrase. There's no official Amazon tool for keyword indexation — this manual search method is the standard approach authors use.

Generate your 7 KDP keywords — tailored to your book.

Includes ghost category paths. Formatted to KDP's 50-character limit. Filtered against Amazon's banned terms list.