By Gyan Prakash Upadhyay | Last updated: November 6, 2026
Amazon KDP keyword research is the step most authors rush. They spend months writing a book and about ten minutes choosing its keywords, then wonder why nobody finds it. On Amazon, keywords connect a reader’s search to your book, so they decide whether your listing is shown or buried among millions of others.
This guide shows how we do Amazon KDP keyword research for our own books at KDP With AI: how to find keywords readers actually type, how to judge competition, and how to fill your seven backend keyword boxes. It works for fiction, non-fiction and low-content books. If you are still choosing what to write, start with how to choose a profitable KDP niche and how to validate a book idea before writing it first.
Amazon KDP keyword research: where your keywords go
Amazon decides which books to show for a search using the information in your listing. Keywords matter in these places:
- Title and subtitle: the strongest signal, and the first thing a reader sees.
- Seven backend keyword boxes: set in your KDP Bookshelf. Each box holds up to 50 characters, and each can contain a phrase, not just one word.
- Categories: where your book is shelved. See our guide to KDP categories.
- Description: written for readers first. Our book description guide covers this.
Amazon already indexes your title and subtitle, so your backend boxes should add new search phrases, not repeat them. For the full picture of how these pieces work together, read our Amazon KDP SEO guide.
What makes a good KDP keyword
A strong keyword has four qualities:
- Relevant: it describes your book accurately. Misleading keywords bring the wrong readers and can get your metadata rejected.
- Searchable: real people type it into Amazon.
- Beatable: the books ranking for it are not all dominated by established bestsellers.
- Buyer intent: the reader wants a solution, a story type or a specific topic, not just browsing.
Long-tail phrases usually win. They are longer and more specific, so fewer books compete for them and the readers who use them know what they want.
| Too broad | Better long-tail phrase |
|---|---|
| fitness | fitness for busy professionals |
| business | small business startup guide |
| self help | build discipline habits |
| mystery | small town cozy mystery with amateur sleuth |
Step 1: Mine Amazon search suggestions
Amazon’s own autocomplete is the best free source for Amazon KDP keyword research because it comes from real customer searches.
- Open Amazon and start typing your topic into the search bar.
- Write down every relevant suggestion.
- Add a letter after your topic (“cozy mystery a”, “cozy mystery b”, “cozy mystery c”) to reveal more suggestions.
- Repeat with different seed words that describe your book.
Save everything in a spreadsheet. At this stage you want quantity: aim for 30 to 50 raw ideas. If you like to brainstorm with AI, our AI Prompt Vault has ready-made prompts you can adapt, but always check each idea against real Amazon results.
Step 2: Analyze the competing books
For each promising phrase, search it on Amazon and open the first ten results. Record what you see:
| Book | Reviews | Best Seller Rank | Cover quality | Categories | Notes |
|---|---|---|---|---|---|
| Book 1 | |||||
| Book 2 | |||||
| Book 3 |
Then read the pattern:
- Easier keyword: several results have few reviews, dated covers, thin descriptions or weak titles. A new book can compete.
- Harder keyword: most results have hundreds or thousands of reviews and strong covers from established authors or publishers.
These are rules of thumb, not guarantees. The Amazon BSR to Sales Estimator helps you turn a Best Seller Rank into an approximate number of daily sales, so you can see whether the top books in a niche actually sell. Once you know which formats earn, our guide to reading your KDP royalties report shows how to check the same thing for your own books.
Example: “cozy mystery series books”
In this search, the first four results show a useful pattern. One single title has about 3,100 reviews, while three multi-book box sets have roughly 150 to 250 reviews each (214, 244 and 150). Several of the box sets are included in Kindle+. That suggests readers of this keyword are happy to buy or borrow collections, and that a well-packaged multi-book set from a newer author is not shut out. Treat this as a starting signal and repeat the check on at least ten results before you decide.
Step 3: Use categories to find more keywords
Categories show how Amazon groups readers’ interests. Open the top-ranking books for your keyword and scroll to the category path and the Product Details section.
Categories that repeat across successful books are good starting points. Choose categories that describe your book honestly. Picking an unrelated category only because it looks less competitive hurts both readers and your reputation with Amazon. KDP lets you choose up to three categories, and our KDP categories guide explains how to pick them.
Step 4: Add data from keyword tools
Amazon autocomplete gets you far, but tools add search volume and competition estimates to your Amazon KDP keyword research.
Free options
- Amazon search suggestions (above)
- Google Trends, useful for spotting seasonal interest and rising topics in non-fiction
- Google search suggestions and People Also Ask, for reader questions
- AnswerThePublic, for question-style ideas
Paid options
- Publisher Rocket: keyword ideas, estimated search volume, competition scores and category data for Amazon books
- Helium 10: deeper keyword and competitor tracking, useful when you publish many books
- Semrush Keyword Magic Tool: Google search demand and keyword ideas, helpful for non-fiction topics and for planning content
One important caution: Semrush’s volume and difficulty numbers describe Google searches and how hard it is to rank a web page. They do not describe Amazon book searches. Use them as a hint about topic demand, and rely on Amazon autocomplete and the competitor check in Step 2 for the book market itself. Also, Google Search Console is not a KDP keyword tool. It only shows searches that bring visitors to your own website.
We also cover free options in more depth in our free KDP keyword tool guide, and you can compare writing and research tools on our AI tools for KDP authors page.
Step 5: Build a shortlist and score it
Take your raw list and give each phrase a quick score from 1 to 3 on each question:
- Does it describe my book accurately?
- Does it look like something a buyer would type?
- Can a new book realistically compete, based on Step 2?
Keep the highest-scoring 15 to 20 phrases. Delete anything vague, misleading or too broad.
Step 6: Fill your seven backend keyword boxes
KDP asks for up to seven keywords, typically short phrases of up to 50 characters. Use each box for a different search idea and avoid repeating the same word across boxes. Amazon already understands that “mystery novel” and “mystery book” are close, so spending two boxes on them wastes space.
Example for a productivity book
- productivity for entrepreneurs
- time management for busy professionals
- focus techniques for remote workers
- daily productivity habits
- morning routine for success
- work from home productivity
- goal setting strategies
Example for a cozy mystery
- cozy mystery with amateur sleuth
- small town mystery series
- culinary cozy mystery
- bakery mystery novel
- funny cozy mystery
- cat lover mystery
- clean mystery book
Fiction vs non-fiction keywords
Readers search differently depending on the kind of book.
- Fiction readers search by genre, trope, setting, character type and tone: “enemies to lovers fantasy”, “small town mystery”, “clean romance”.
- Non-fiction readers search by problem, skill or outcome: “budget planning for beginners”, “learn Python”, “public speaking tips”.
Think like the reader, not the author. Ask: what would someone type into Amazon to find a book like mine?
Common Amazon KDP keyword research mistakes
- Single generic words. “Romance” or “cookbook” are far too competitive. Use specific phrases.
- Repeating the same word in several boxes. It wastes slots.
- Using other authors’ names or brand names. This breaks Amazon’s metadata guidelines and can get your keywords removed or your book flagged.
- Repeating your title and subtitle. Amazon already indexes them.
- Misleading keywords. They bring clicks without sales and hurt your listing.
- Never updating them. Keyword research is not one-and-done.
Repeat your Amazon KDP keyword research every few months
Look at your listing every 60 to 90 days. Update keywords if sales slow down, a new competitor appears, or you find a better phrase. After you change keywords in your Bookshelf, allow a few days for Amazon to reflect the change, and change one thing at a time so you can tell what worked.
Amazon KDP keyword research checklist
- ☐ Brainstormed 30 to 50 raw ideas from Amazon autocomplete
- ☐ Checked the top 10 results for each promising phrase
- ☐ Reviewed categories used by successful books
- ☐ Confirmed demand with at least one tool or data source
- ☐ Shortlisted 15 to 20 phrases
- ☐ Filled seven unique backend boxes
- ☐ Kept competitor names and misleading terms out
- ☐ Added a reminder to review keywords in 60 to 90 days
Frequently asked questions
How long does Amazon KDP keyword research take?
For a new book, plan on roughly a couple of hours: gather ideas, check the competition, then shortlist and fill your seven boxes. Updating an existing listing later is much faster.
How many keywords can I use on Amazon KDP?
Seven backend keyword boxes, each typically a short phrase of up to 50 characters.
Can I change my KDP keywords after publishing?
Yes. You can edit them from your Bookshelf at any time. Changes can take a few days to show up.
Should I put keywords in my book title?
Only when they fit naturally. A clear, keyword-aware subtitle usually works better than forcing keywords into the main title.
How long should a keyword phrase be?
Phrases of about three to five words usually balance relevance and competition well.
Do I need a paid keyword tool?
No. Start with Amazon autocomplete and a competitor spreadsheet. Consider a paid tool once you publish regularly.
Can I use AI to find keywords?
You can use an AI assistant to brainstorm and group ideas, but always check each phrase against real Amazon results before you use it. See our AI tools for KDP authors for tools we recommend.
Is keyword research worth the time if KDP income is slow?
Yes, it is one of the cheapest ways to improve a listing. If you are weighing whether to continue at all, read Is KDP still worth it in 2026? for an honest look at earnings and costs.
Final thoughts
Good Amazon KDP keyword research is a repeatable process: gather real search phrases, check the competition, shortlist the best ones and fill your seven boxes with different, relevant ideas. Do it before you publish, then revisit it every few months. Pair it with a strong title, cover and description, and read our Amazon KDP SEO guide for the full picture. Once your listing is ready, our guide to getting your first 100 book sales on Amazon KDP shows what to do next.
If you would rather have an expert handle your metadata, see our Amazon KDP SEO services or contact us.
About the author: Gyan Prakash Upadhyay is the founder of KDP With AI and a KDP publishing strategist. Under his direction, more than 75 books have been published on Amazon KDP. See the books on the Amazon author page.