You've written a great book, but if readers can't find it, they can't buy it. Amazon KDP gives you seven keyword slots and two category choices to help readers discover your book. Used well, these metadata elements can dramatically increase your visibility and sales. Used poorly, or left as an afterthought, you're leaving money on the table.
Keyword research isn't guessing or filling in generic terms. It's strategic research into how readers actually search for books like yours, what terms have searchable volume but manageable competition, and where you can realistically rank. This guide will show you how to find keywords that actually sell books.
Understanding Amazon's Keyword System
First, understand what Amazon does with your keywords and how they work.
The seven keyword boxes: When you publish on KDP, you get seven text boxes for keywords. Each can hold multiple words (up to 50 characters per box). Amazon indexes all the words you put in these boxes and uses them to determine when your book appears in search results.
How Amazon uses keywords: - Matching search queries to your book - Determining which searches show your book - Ranking your book for those searches (based on sales velocity, reviews, clicks, and other factors) - Suggesting your book in "customers also bought" and recommendations What keywords DON'T do: - They don't guarantee ranking - They don't directly affect Amazon's bestseller rank (though indirectly by driving traffic) - They don't replace the need for good categories - They don't compensate for poor cover, description, or reviews
Keywords help Amazon connect your book to searchers. But you still need to convert those searchers into buyers.
Other metadata that matters: - Title and subtitle (Amazon indexes these heavily) - Book description (indexed for keywords too) - Categories (choose wisely, can change later) - Author name (also indexed) - Series name
Your keywords work with these other elements. Don't just rely on the seven keyword boxes. Strategic keyword placement throughout your metadata matters.
The Difference Between Keywords and Categories
Keywords and categories are related but different tools.
Categories: These are the browse structure on Amazon. Readers can browse by category ("Kindle Store > Science Fiction & Fantasy > Fantasy > Epic"). You get two primary categories, but your book can appear in multiple categories based on keywords and Amazon's algorithms. Categories affect bestseller lists and visibility in browse.
Keywords: These are search terms. When someone types "vampire romance with strong heroine" into Amazon's search bar, your keywords determine if your book shows up. Keywords affect search visibility and ranking.
Good strategy uses both. Choose categories where you can rank highly (smaller categories often better than huge competitive ones). Use keywords to capture search traffic for specific terms readers actually use.
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Research Your KeywordsHow to Find Keywords: The Amazon Autocomplete Method
The best free keyword research tool is Amazon itself. The search bar autocomplete shows you what real readers actually search for.
Step-by-step: 1. Go to Amazon.com and click in the search bar 2. Make sure you're in "Kindle Store" or "Books" (use the dropdown) 3. Type a word or phrase related to your book 4. Note the autocomplete suggestions that appear 5. These suggestions are based on actual search volume - Amazon shows popular searches 6. Try variations and note which suggestions appear
Example for a fantasy romance: Type: "fantasy romance" Autocomplete shows: - fantasy romance books - fantasy romance kindle unlimited - fantasy romance series - fantasy romance with strong female lead - fantasy romance enemies to lovers
These are real search terms people use. Note them.
Now get more specific: Type: "fantasy romance with" Autocomplete shows: - fantasy romance with fae - fantasy romance with magic - fantasy romance with dragons - fantasy romance with spice
Keep drilling down. Try your specific subgenre, tropes, settings, character types.
Pro tip: The autocomplete order indicates relative popularity. Terms appearing first typically have higher search volume than terms appearing last.
Analyzing Competitor Keywords
Your successful competitors (books similar to yours that are selling well) can reveal what keywords work.
How to reverse-engineer competitor keywords: 1. Find 3-5 books very similar to yours that are bestsellers in your niche 2. Search for each book on Amazon 3. Note which searches bring up that book in the first page of results 4. Look at their categories (visible on book page) 5. Read their book descriptions for repeated terms 6. Check their title and subtitle for keyword placement 7. Use tools like Publisher Rocket or KDP Rocket to see estimated keywords (these tools cost money but provide data)
Manual method: Take a competitor book title and search variations: - "books like [competitor title]" - Look at Amazon's "customers who bought this also bought" section - Note what terms Amazon uses to describe similar books - Check what searches show that book ranked
What you're looking for: - Terms that appear for multiple successful books in your niche - Specific multi-word phrases ("enemies to lovers fantasy" not just "fantasy") - Niche descriptors your book actually fits - Terms you might not have thought of but readers use
Reader Language vs Author Language
Authors think about books differently than readers search for them.
Author language: "A tale of redemption and self-discovery set in a magical realm" Reader language: "fantasy with magic school", "enemies to lovers fantasy", "fantasy romance kindle unlimited"
Authors think in themes and literary concepts. Readers search for genre, tropes, specific elements, and delivery format. Use reader language in your keywords.
How to find reader language: - Read reviews of books like yours - what terms do readers use? - Join reader Facebook groups for your genre - how do they describe books? - Look at Amazon Q&A sections on competitor books - Check Goodreads discussions - Note how readers tag books on Goodreads
If readers describe books like yours as "slow burn fantasy romance," that's a keyword phrase worth testing even if you'd describe your book differently.
Choosing Your Seven Keywords
You have seven boxes. How do you fill them strategically?
Keyword box strategy: Box 1-2: Your core genre/subgenre keywords These are broad but essential. They define what your book IS. - "fantasy romance" - "paranormal romance werewolf" Box 3-4: Specific tropes or elements More specific terms that describe your book's appeal. - "enemies to lovers fantasy" - "fated mates werewolf romance" Box 5-6: Niche descriptors or reader-specific searches Very specific terms that might have lower volume but also lower competition. - "fantasy romance with strong female lead and slow burn" - "werewolf romance alpha possessive" Box 7: Comp title or format-specific - "books like fourth wing" (if your book legitimately compares) - "kindle unlimited fantasy romance" (if you're in KU)
Guidelines: - Use your full 50 characters per box when possible - Include multiple related terms in each box (Amazon indexes all words) - Don't repeat the exact same phrase in multiple boxes (use variations) - Don't waste space on single words that are too broad ("romance" alone is useless) - Include format if relevant ("kindle unlimited", "audiobook") - Use natural phrases readers would actually type
Example for a fantasy romance: 1. fantasy romance books with magic 2. enemies to lovers fantasy romance series 3. slow burn fantasy romance strong female lead 4. fae romance fantasy books 5. fantasy romance kindle unlimited spicy 6. adult fantasy romance completed series 7. books like a court of thorns and roses
Notice: Each phrase is specific, multiple words, uses reader language, and targets different aspects of the book.
Long-Tail Keywords: Your Secret Weapon
Long-tail keywords are longer, more specific phrases. They typically have lower search volume but also much lower competition. They're often easier to rank for and attract more qualified buyers.
Short/broad keyword: "mystery" - High search volume - Extreme competition - Vague (what kind of mystery?) - Hard to rank Long-tail keyword: "cozy mystery with cats and bakery setting" - Lower search volume - Much lower competition - Specific (targets exact readers) - Easier to rank - Readers who search this are more likely to buy
For most indie authors, long-tail keywords perform better than broad terms. You might get fewer impressions, but your conversion rate (impressions to sales) will be higher because you're reaching readers specifically looking for what you offer.
How to build long-tail keywords: Start with your genre, add your subgenre, add your trope or setting or character type. - Genre: mystery - Subgenre: cozy mystery - Setting: small town cozy mystery - Character: small town cozy mystery with female detective - Add element: small town cozy mystery with female detective and dog
Test which length performs best for your book.
Keyword Competition Analysis
Not all keywords are created equal. You need to assess whether you can actually rank for a keyword.
How to check competition: 1. Search the keyword on Amazon (in Kindle Store) 2. Look at the number of results (shown at top of search) 3. Look at the books ranking on page 1 4. Ask yourself: - How many total results? (under 1,000 is low competition, 1,000-10,000 is medium, 10,000+ is high) - What are the bestseller ranks of books on page 1? (if they're all under 10,000 BSR, it's competitive) - How many reviews do page 1 books have? (if they all have 500+ reviews, hard to compete) - Are any of the page 1 books similar to your quality level?
Can you compete? If page 1 is all books with 2,000+ reviews, 5-star averages, and bestseller ranks under 5,000, you probably can't rank on page 1 as a new author. That doesn't mean don't use the keyword, but don't expect to rank highly for it.
Better to target keywords where page 1 includes some books with 50-200 reviews, bestseller ranks in the 20,000-100,000 range, and quality comparable to yours. You can compete there.
The Goldilocks zone: Look for keywords with: - Enough search volume to matter (appears in autocomplete is a good sign) - Manageable competition (page 1 isn't all megahits) - High relevance to your book (actually describes what you wrote) - Buyer intent (people searching this are looking to buy, not just browse)
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Analyze Your KeywordsTesting and Iterating Keywords
Keyword research isn't one-and-done. It's ongoing optimization.
Initial keyword strategy: Launch with your best-researched keywords. Give them 30-60 days to generate data.
Track performance: Use Amazon Author Central or KDP dashboard to see: - Which search terms are driving impressions - Which are driving clicks - Which are driving sales - Your book's rank for specific searches
KDP doesn't show you everything, but you can see some data. Third-party tools like Publisher Rocket provide more detailed tracking.
When to change keywords: - If you're getting zero traction after 60 days - If you notice a keyword that's driving impressions but zero clicks (wrong audience) - If you launch in a new category or series and want to optimize for that - If you discover better keywords through research or competitor analysis - Seasonally (holiday keywords, summer reads, etc.) When NOT to change keywords: - In your first 30 days (give them time to work) - Every week (too frequent changes confuse Amazon's algorithm) - If something is working (don't fix what isn't broken)
Test methodically: Change 1-2 keywords at a time, not all seven. Track what happens to your sales and rank over the next 30 days. If things improve, keep the new keywords. If things get worse, revert or try different keywords.
Category Strategy
Categories work with keywords but require different strategy.
You get two primary categories: Choose these carefully when you publish. You can change them later by contacting KDP support.
Small categories > Big categories: Would you rather be ranked #100 in "Fantasy" (where you're invisible) or #5 in "Fantasy > Epic Fantasy > Dragons" (where readers might actually see you)?
Smaller, more specific categories are easier to rank in. Being a bestseller in a small category (which displays a "bestseller" tag) is more valuable than being #10,000 in a huge category.
Browse categories on Amazon: Go to Kindle Store > Browse categories > Your genre > Keep clicking into subcategories until you find narrow ones that fit your book. These are categories you can request via KDP support.
Category keywords: Some categories can be accessed through keywords. For example, including "time travel" in your keywords might get you into time travel romance categories. Research which keywords unlock which categories.
Optimal strategy: Choose two different narrow categories where you can rank on page 1 or 2. Don't choose the same category twice. Maximize your visibility across different browse paths.
Title and Subtitle Keyword Integration
Amazon heavily weights your title and subtitle in search. Use this strategically.
Fiction title strategy: Your main title is usually your creative book title. But your subtitle can include keywords. Example: Shadow's Edge (creative title) A Dark Fantasy Romance (subtitle with keywords)
Full title on Amazon: Shadow's Edge: A Dark Fantasy Romance
This gets "dark fantasy romance" indexed from your title, leaving your seven keyword boxes free for other terms.
Nonfiction title strategy: Nonfiction titles should be very keyword-rich because readers search for topics and solutions. Good: Dog Training Essentials: The Complete Guide to Positive Reinforcement Training for Puppies and Adult Dogs
This title includes multiple keywords: dog training, positive reinforcement training, puppies, adult dogs. Readers searching any of these terms might find this book.
Don't keyword-stuff to the point of ugly: Your title still needs to sound good and be readable. Don't create a title that's just a string of keywords. But do be strategic about including 2-3 relevant terms.
Book Description Keyword Optimization
Amazon indexes your book description for search. Use it wisely.
Natural integration: Don't keyword-stuff your description. But do naturally include important terms readers search for. If readers search "slow burn enemies to lovers," make sure that phrase appears in your description naturally: "This slow-burn enemies-to-lovers fantasy will keep you turning pages all night."
First 150 characters matter most: Amazon shows the first ~150 characters of your description in search results and on mobile. Include your most important keywords here naturally.
Repeat key terms 2-3 times: If "cozy mystery" is your primary keyword, use it 2-3 times in your description (naturally, not stuffed). Repetition reinforces to Amazon what your book is about.
Common Keyword Mistakes
Using single broad words: "romance", "mystery", "fantasy" alone are too broad. Add specificity.
Ignoring format: If you're in KU, "kindle unlimited [genre]" is a valuable keyword because many readers specifically search for KU books.
Using author names: Don't waste keyword space on your own name (already indexed) or other authors' names unless you're specifically targeting "fans of [author]" searches and your book legitimately compares.
Keyword stuffing: Filling boxes with every possible word: "fantasy romance love magic dragons elves witches werewolves." This doesn't work as well as coherent phrases.
Not updating ever: Setting keywords once and never revisiting them. Markets change, trends change, your strategy should evolve.
Copying competitors exactly: You can learn from competitors, but don't copy their exact keywords. You're competing for the same searches. Find related but different keywords where you have a better chance to rank.
Ignoring your actual book: Using popular keywords your book doesn't actually match. If your book isn't enemies-to-lovers, don't use that keyword. Disappointed readers leave bad reviews.
Seasonal and Trending Keywords
Some keywords have seasonal relevance. Use this strategically.
Holiday keywords: - "Christmas romance" peaks in November-December - "summer beach read" peaks May-August - "Halloween horror" peaks September-October - "Valentine's Day romance" peaks January-February
If your book fits, add seasonal keywords 6-8 weeks before the season. Remove them after the season ends to make room for evergreen keywords.
Trending keywords: If a comp title goes viral (like "Fourth Wing" did), "books like [trending title]" becomes a hot keyword. If your book genuinely compares, add this keyword while it's trending.
Monitor trends through: - Amazon bestseller lists - BookTok and Bookstagram - Publisher's Marketplace - Google Trends for books But only use trending keywords if your book actually fits. Don't mislead readers.
Tools to Make Keyword Research Easier
Free tools: - Amazon's autocomplete (best free tool) - Amazon search results analysis - Goodreads tags and shelves - Reader groups and reviews - Google Keyword Planner (shows some Amazon search data)
Paid tools (one-time or subscription): - Publisher Rocket / KDP Rocket ($97 one-time): Keyword research, category finder, competition analysis - KDSpy (Chrome extension, $47 one-time): See estimated sales and keywords for books - Helium 10 (subscription): More robust tool, overkill for most authors Paid tools save time and provide data you can't easily get manually. But you can do effective keyword research for free if you're willing to invest the time.
Your Keyword Research Checklist
Before finalizing your keywords: - Used Amazon autocomplete to find actual reader search terms - Analyzed 3-5 successful comp titles for their keywords and categories - Identified long-tail keywords specific to your book - Checked competition level for each keyword (can you rank?) - Balanced popular keywords with niche keywords - Integrated keywords into title/subtitle where possible - Optimized book description with natural keyword inclusion - Chose two narrow categories where you can rank - Avoided keyword stuffing and misleading terms - Planned to test and iterate after 30-60 days - Set up tracking to measure keyword performance Keyword research is part science (data and competition analysis), part art (understanding reader psychology), and part persistence (testing and iterating). Do it well, and you'll dramatically increase your book's discoverability. Your book might be amazing, but if readers can't find it, they can't buy it. Keywords are how you get found. Invest the time to get them right.