How to Do a Reverse ASIN Search for Books (Step by Step)

You have a book idea, or a book already written, and you need keywords. You could guess. Or you could look at what books written for the same readers already show up for. That second approach is a reverse ASIN search, and it is one of the more practical research habits a self-publisher can build.

This guide explains the method first, so you can follow it with or without a tool. Then I will show how AuthorScout does the same job, and where its limits are.

What a reverse ASIN search is

An ASIN is Amazon's 10-character product identifier. For a book, you can find it in the product details, or in the Amazon link right after /dp/.

A normal keyword search starts with a phrase and shows you books. A reverse ASIN search flips it. You start with a book and get back phrases that book appears for in Amazon search. Those phrases are clues about how real readers describe what they want.

Why authors use it

• It shows reader language. You may call your book a guide to emotional regulation. Readers may type something different. Seeing the wording around competing books helps you spot the gap.
• It surfaces phrases you did not think of. Brainstorming only gets you so far.
• It gives you a starting list, not a final one. You still decide what fits.

One honest note: the keywords a book appears for are a result of many things, including its title, its description, its sales history and Amazon's own systems. They are not a recipe you can copy. Treat them as research ideas.

The step-by-step method

Step 1: Pick comparable books

Choose 3 to 5 books that are written for the same readers as yours. Same subject, same level, same kind of promise. A book with a similar topic but a different audience will send you in the wrong direction.

Good picks are books that are selling steadily and have been around long enough to have built up search visibility. If you want help finding books worth studying, Profitable Titles lists books that show demand with relatively few reviews, which is a useful starting pool.

Step 2: Copy each book's ASIN

Open the Amazon listing and copy the ASIN. Make sure you use the edition you want to study. Kindle, paperback and hardcover editions can have different ASINs.

Step 3: Run the search

Enter the ASIN into a reverse ASIN tool and collect the phrases it returns. Do this for each comparable book, and keep every result in one spreadsheet. A simple column layout works: phrase, which book it came from, position if shown, search volume if shown.

Step 4: Read the results properly

Do not just sort by the biggest number. Look for these things:

• Phrases that repeat across several books. If three of your four comparable books show up for the same phrase, readers probably use it.
• Organic versus sponsored positions. Organic means regular search results. Sponsored means paid ads. A book can appear in either or both, and they tell you different things. A phrase where a book only shows as an ad is not evidence the book ranks for it naturally.
• Volume, treated as an estimate. Search volume figures from any tool are estimates. Use them to compare phrases against each other, not as exact counts.

Step 5: Filter out the noise

This is where most of the value is. Remove:

• Brand names and series names. A phrase containing a publisher or series name is only relevant to that product.
• Other authors' names. People searching an author's name want that author. Do not put another author's name in your keywords.
• Phrases for a different audience or format. A workbook phrase does not belong on a narrative book, and the reverse.
• Anything vague or off-topic that you cannot honestly connect to your book.

Step 6: Turn the results into a short keyword list

Group what is left by meaning. You will usually see clusters, such as the problem readers have, the type of reader, and the format. Pick the strongest phrase or two from each cluster. You are aiming for a short list, not a pile.

KDP gives you a limited number of keyword slots at upload, and the rules can change, so check KDP's current limits in the KDP help pages before you finalize anything.

Step 7: Check fit against your own book

For every phrase left, ask: would a reader who searched this be glad to land on my book? If the honest answer is not really, cut it. A relevant phrase with modest volume usually serves you better than a popular phrase that attracts the wrong buyer.

Common mistakes

• Copying a competitor's whole list. Their book is not your book. Use their results as ideas.
• Studying only one book. One book can have odd quirks. Patterns across several are more reliable.
• Ignoring the audience. A book that looks similar may be aimed at someone different.
• Trusting volume as exact. It is a rough guide.
• Stuffing in names. Other authors' names and brands are noise at best, and may break KDP's rules. Read KDP's current metadata guidelines.
• Doing it once and forgetting. Markets change. Revisit your keywords now and then.

Doing it by hand without a tool

You can do a rough version for free. Type the book's main topic into Amazon's search bar and note the autocomplete suggestions. Open the comparable books and read their titles, subtitles and descriptions for the phrases they use. Look at the Also bought and sponsored sections for related books.

It works, and I did it this way for a long time. But it is slow. You cannot see where a given book actually shows up in search, you do not get volume estimates, and comparing five books across dozens of phrases means a lot of tabs and a lot of copying. That is the gap a tool fills.

How AuthorScout's Reverse ASIN Search does it

AuthorScout's Reverse ASIN Search follows the same method with the legwork done for you.

1. Enter the ASIN of a relevant book.
2. See the returned keywords, with available monthly search estimates and search positions.
3. Compare organic and sponsored positions, filter the phrases, and export the results into your spreadsheet.

From there you can take promising phrases into Keyword Research, which starts from a topic or phrase rather than a book, to see related ideas and estimates.

The limits, stated plainly

• Reverse ASIN Search is a Publisher Pro feature, with 50 searches a month.
• It covers the Amazon US marketplace.
• A search returns up to 50 keywords. Some books return fewer, and some results are missing position or search-volume data.
• You will not see every keyword a book ranks for. The results reflect the data available.
• Search volumes are estimates.

It speeds up the research. It does not decide for you which phrases fit your book. That step is still yours.

FAQ

What is an ASIN?

It is Amazon's 10-character product identifier. Find it in the product details on the listing or in the link after /dp/. Use the ASIN for the edition you want to research.

Will a reverse ASIN search show every keyword a book ranks for?

No. Any tool only shows the ranking data it has access to. With AuthorScout, one search returns up to 50 keywords.

What is the difference between organic and sponsored?

Organic positions are regular search results. Sponsored positions are paid ads. A book can appear in either or both.

Should I copy a competitor's keywords?

Use them as ideas. Keep only the phrases that accurately describe your book and its readers.

How is this different from keyword research?

Keyword research starts with a topic or phrase. Reverse ASIN starts with an existing book and looks at what it appears for.

Where to go from here

Pick three comparable books today, copy their ASINs, and build the spreadsheet. If you would rather skip the manual work, you can run the same search in AuthorScout. Either way, the aim is the same: publish with data, not guesses.