KDP Keyword Research in 2026: How to Fill the 7 Slots Without Paid Tools

What the 7 keyword slots actually do

When you set up a title in KDP, you get seven keyword fields. Each one accepts a short phrase (check the current character limit in KDP’s help pages). These phrases are never shown to shoppers. They feed Amazon’s search index alongside your title, subtitle, description and categories.

Three things follow from that:

• Each slot is a phrase, not a single word. “journal prompts for anxiety” is one entry; you do not need commas inside a slot.
• Words already in your title and subtitle are indexed anyway. Spending a slot on them is a waste.
• Word order inside a slot matters less than the words themselves. Amazon matches on terms, so “beginner sourdough bread” also covers searches for “sourdough bread beginner”.

Treat the seven slots as seven distinct angles on how a reader might search for your book, not seven variants of the same phrase.

Start with the search bar

Amazon’s autocomplete is the most honest free research tool you have. It suggests phrases that real shoppers type, ranked loosely by how often they are searched.

Work through this routine:

1. Open Amazon in a private browser window so your own history does not skew suggestions. Set the search dropdown to Kindle Store or Books, depending on your format.
2. Type your core topic and stop. Note every suggestion.
3. Add a letter: “sourdough a”, “sourdough b”, and so on through the alphabet. Record anything relevant.
4. Try the reader’s intent words: “for beginners”, “for kids”, “workbook”, “guide”, “large print”, the current year.
5. Repeat for two or three adjacent topics a reader of your book might also search.

You will end up with a list of thirty to sixty phrases. That list is your raw material.

Read competitor listings

Pick five to ten books that sit on page one for your main phrase and are close to yours in format and length. For each one, look at:

• Title and subtitle. The phrases publishers put here are the ones they believe convert. Patterns across several books tell you the vocabulary of the niche.
• Description. Read the first paragraph. Which terms repeat?
• Categories. Scroll to the product details and note the Best Sellers Rank categories. This feeds into your category choice later; see choosing KDP categories.
• Also-bought row. The books Amazon pairs with a competitor show you which neighbouring searches overlap.

You are not copying anything. You are learning what words the market already uses, so that your metadata speaks the same language.

Judge demand against competition

Without paid tools, you can still make a reasonable call for each phrase.

Demand signals

• It appears in autocomplete. If Amazon suggests it, people type it.
• It appears early in the suggestion list rather than at the bottom.
• Several page-one results use it in their title or subtitle.

Competition signals

• Search the exact phrase and look at the total results count. A phrase with a few hundred results is easier to rank for than one with tens of thousands.
• Look at the Best Sellers Rank of the books on page one. If the top results all hold very strong ranks, the phrase is contested. If several page-one books have weak ranks, there is room.
• Check how many page-one results come from large publishers or established series. Independent books on page one are a good sign for you.

How to choose

Aim for a mix. One or two slots for your broadest phrase, even though it is competitive. Three or four for mid-level phrases with clear demand and visible gaps on page one. The rest for specific long-tail phrases where you can plausibly be the best match. This spread gives you some traffic on day one and a path to growing into the bigger phrases later.

What to avoid

KDP’s metadata guidelines are enforced, and a violation can delay publishing or get a listing suppressed. Keep these out of your keyword slots:

• Other authors’ names or book titles. This is the most common violation and the easiest for Amazon to detect.
• Brand names and trademarks you do not own, including “Kindle” and “Amazon” themselves.
• Subjective claims. “Best”, “bestselling”, “number one”, “award-winning” are not keywords; they are claims, and KDP treats them as misleading.
• Temporary promotional phrases such as “free”, “sale”, “new” or “on sale now”.
• Words already in your title, subtitle or category path. Not a violation, just a wasted slot.
• Irrelevant phrases added for traffic. If someone searching that phrase would be disappointed by your book, leave it out. Mismatched keywords lead to clicks without sales, which works against you in ranking.
• Unrelated genres or formats. Do not tag a colouring book as a novel.

Read the current KDP metadata guidelines before you submit. They are short, and they change.

Revisit after launch

Keywords are not a one-time decision. After the book has been live for a few weeks:

• Search each of your seven phrases and note where you appear.
• Swap any phrase that is not surfacing your book within the first few pages for the next candidate on your list.
• If you run Amazon Ads, the search term report shows you real queries that led to sales. Those are strong candidates for your slots.

Keep your research list in a spreadsheet so this takes minutes rather than hours.

Next step

Keywords get you into the index; categories decide which lists you can appear on. Read how to choose KDP categories next to pick the three categories you set at upload and learn how to request more. Then bring both into your final review with the pre-publish checklist.