Free KDP Keyword Research: 6 Methods That Cost Nothing
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Free KDP keyword research is possible, and it's more accurate than most people think, because the best data comes from Amazon itself. Use Amazon's search suggestions to find what readers type, study the books that already rank, check Google and YouTube for demand outside Amazon, then pick seven focused phrases that follow KDP's keyword rules. No paid tool required.
Below are six free methods, a worksheet for filling KDP's seven keyword boxes, and the mistakes Amazon says to avoid.
How KDP keywords actually work
When you set up a book, KDP gives you room for up to seven keywords or short phrases. Amazon says relevant keywords, together with things like sales history and Best Sellers Rank, can boost your placement in search results.
A few rules from KDP's own guidance shape everything below:
- Keywords should describe your book's content and match words customers actually search for
- Don't repeat what's already in your title, contributor names or categories
- Don't use quotation marks; single words and specific phrases work better
- Avoid other authors' names, brands you don't own, "bestselling," "free," "new," and "book"
- You can change keywords as often as you like
KDP's metadata guide adds one more useful hint: phrases of 2–3 words tend to work best.
Method 1: Amazon search suggestions (the best free tool)
KDP's keyword page tells you to search your ideas on Amazon before publishing and to "look at the suggestions that appear in the Search field drop down." Those suggestions reflect what shoppers type.
How to do it:
- Open Amazon, switch the search category to Books (or Kindle Store for eBooks).
- Type your seed phrase slowly and write down every suggestion.
- Add words after your seed: "for," "with," "small," "large print," and each letter of the alphabet.
- Repeat in a private browser window so your history doesn't skew suggestions.
For example, when we typed "password book" into Amazon's Books search on October 27, 2026, the suggestions included "password books for seniors" and "password book small." That tells you two specific angles buyers already search for: an audience and a size.
Tip: suggestions change over time and by marketplace. Check Amazon.co.uk or Amazon.de separately if you plan to sell there.
Method 2: Study the books that already rank
Search each promising phrase and open the first page of results. For the top books, note:
- Title and subtitle wording. Which words repeat across sellers?
- Best Sellers Rank on the product page. KDP names it, along with sales history, as one of the factors in search placement.
- Number and age of reviews. A page full of books with thousands of reviews is harder to break into than one with a mix of newer titles.
- Categories shown under the rank. These hint at where buyers browse.
Keep a simple table:
| Phrase | Top results match it closely? | Strong competitors on page 1 | Room for a better book? |
|---|---|---|---|
| password book small | |||
| password books for seniors |
You're looking for phrases where readers clearly search, but the results don't serve them well.
Method 3: Mine the reviews for buyer language
Open three or four top competitors and read the 2- and 3-star reviews. Buyers describe what they wanted in their own words: "large print," "spiral bound," "for my dad who has dementia," "pocket size." Those phrases are often perfect keywords and better product ideas than anything a tool will give you.
Method 4: Google and YouTube autocomplete
Amazon shows what people search when they're ready to buy. Google and YouTube show what people are curious about before that. Type your topic into Google and YouTube and note the suggestions, especially "how to," "for beginners," and "best" phrases.
When we ran this for the topic of this article, Google suggested phrases like "kdp keyword research tool free" and "amazon kdp keyword research free," which is why this guide focuses on free methods.
This is especially useful for nonfiction: if people search "how to start beekeeping" on Google, a beginner beekeeping guide or hive log book has visible demand.
Method 5: Google Trends for timing
Google Trends is free and shows how interest in a search term rises and falls over time. Use it to:
- Spot seasonal books (planners, holiday activity books, garden journals) and publish well before the peak
- Compare two phrasings, like "journal" vs. "diary," for your topic
- Avoid fads that spiked once and faded
Remember that low-content books can take longer to review. KDP's Book Status page says reviews for journals and notebooks may take 3–4 weeks, so leave room before seasonal peaks.
Method 6: Use AI to organize, not to invent
AI chat assistants don't have Amazon's search data, so don't ask them which keywords "get the most searches." They'll guess. Instead, paste in the real phrases you collected and ask:
Here are 40 search phrases I collected from Amazon suggestions and reviews for a password book. Group them by intent (audience, size, feature, gift occasion). Remove duplicates and plurals. Suggest 7 keyword phrases of 2–3 words that don't repeat words from this title: "[your title]".
Then check every suggested phrase against Amazon search again. If the results look irrelevant, drop it. That's straight from KDP's advice.
Filling your 7 keyword boxes: a worksheet
Use one box per idea, and don't waste space repeating words.
| Box | What to put there | Example (title: "Large Print Password Book") |
|---|---|---|
| 1 | Main audience | seniors internet address log |
| 2 | Key feature | alphabetical tabbed pages |
| 3 | Use case | website login organizer |
| 4 | Format or size | small discreet notebook |
| 5 | Gift angle | gift for grandparents |
| 6 | Synonym buyers use | login keeper logbook |
| 7 | Related need | home office organization |
Notice what's missing: no "book," no "bestselling," no brand names, and nothing already in the title. KDP lists all of those as things to avoid. Also skip plural or spacing variants ("password" and "passwords"), which KDP says not to add.
Mistakes that waste your keywords
- Stuffing the title. KDP prohibits repeating generic words like "notebook," "journal" or "gifts" in the title field. Put descriptive phrases in keywords instead.
- Using quotes. If you type a phrase in quotation marks, KDP says only people who type all those words will find you.
- Copying competitors' author names or brands. That's a metadata violation.
- Never updating. You can change keywords whenever you like, so revisit them after a few weeks of sales data.
If you're building a book with AI, our guides on creating low-content books with AI and making a children's book with AI show where keyword research fits in the process.
FAQ
What is the best free KDP keyword research tool?
Amazon's own search bar. KDP recommends searching your keyword ideas on Amazon and checking the drop-down suggestions before publishing. Combine it with competitor research and review mining for the best free results.
How many keywords can I add on KDP?
KDP lets you add up to seven keywords or short phrases per book. Keep an eye on the character limit in each field, and use 2–3 word phrases for best results.
Should I repeat my title words in my keywords?
No. KDP says to avoid information already covered in your title, contributors or categories. Use the keyword boxes for new, relevant terms.
Can I change my KDP keywords after publishing?
Yes. KDP says you can change keywords and descriptions as often as you like. Edit them from your Bookshelf under "Edit book details," then republish.
Can ChatGPT do KDP keyword research?
Not on its own. AI assistants don't see Amazon's search data, so treat their keyword ideas as guesses. Use AI to group and clean the real phrases you collect from Amazon, then confirm each one with an Amazon search.
Conclusion
The most reliable keyword data for KDP is free: Amazon's suggestions, the books that rank, and the words buyers use in reviews. Collect real phrases, organize them with AI if it helps, follow KDP's rules, and revisit your keywords as you learn.
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