The Best Free Amazon Keyword Research Tools

Scientific Seller Keyword Tool Logo
1. Scientific Seller Keyword Tool

— Product Details Scientific Seller provides keyword suggestions for Amazon listings and PPC ads, generated from an initial…

SellerSonar Logo
2. SellerSonar

— Product Details SellerSonar is software that monitors changes to sellers’ Amazon listings and sends alerts and notifications. …

Sonar Logo
3. Sonar

— Sonar is a keyword research tool that helps e-commerce sellers optimize product listings, particularly on Amazon. It…

A while back, we did some research on the best free eBay selling tools. This process made us realize just how useful free tools can be for online sellers and we wanted to provide our readers with an Amazon equivalent. So, we donned our deerstalker hats and began tracking down some useful free keyword research tools for Amazon sellers.

For each tool we’ve identified what it does, how it works and why you might want to use it.

Free Isn’t Always Free

What exactly do we mean by “free”? There are so many shades of free these days that it needs a little explanation. The software we’re looking for should be free forever, not just a free trial for 14 days before you have to pay.

Free plans will usually have limits, or come with ads or promotions for paid tools, but that’s OK as long as they provide genuinely useful features for free. After all, companies have to make money somehow or they won’t be around for very long.

1. Sonar

Our first keyword tool is Sonar. Developed by Sellics, Sonar allows users to search a database of over 180 million keywords. Sellers can improve how they rank organically for certain keywords or optimize their Pay Per Click (PPC) advertising campaigns.

There are three different keyword searches that you can do using Sonar, across six global marketplaces (USA, UK, France, Italy, Spain and Germany). The first is a standard keyword search, where you enter a keyword and receive suggestions that combine your keyword with popular search terms. For instance, if my keyword was “golf balls”, the suggestions would include “used golf balls”, “callaway golf balls” and “practice golf balls”.

The second option, an extended search, builds on the keyword search but also adds synonyms and related terms. So with my keyword still as “golf balls”, I get suggestions I may not necessarily have thought of, like “golf accessories” and “refurbished golf balls”.

The final option is a reverse ASIN search. For this keyword search, you simply enter an ASIN and it will tell you the keywords that it ranks for. This means that you can see what your competitors are doing, and even copy the keywords that have high search volume scores.

When you do any of these searches, there is an option to “exclude permutations”, which is set to “yes” by default. This means that your search won’t return results that include the same words, just in a different order. So for instance if the search found “yellow golf ball” and “golf ball yellow” it would only include the one with the higher search volume.

In theory you would want to use all three of these searches, in order to undertake thorough keyword research. You could start with a reverse ASIN search and list the keyword suggestions which receive the highest estimated search volume (those with red and orange bars). You can then take these and put them through an extended search, as finding synonyms increases your pool of potential keywords.

The final step is to put the ones you think are the most important through a keyword search, to generate as many relevant combinations with the highest search traffic as possible. These keyword suggestions can then be used within your product listing, in a PPC campaign, or in both.

Regardless of which of these searches you conduct, the results page is presented in the same way. You will see a list of keywords on the left-hand side, accompanied by a series of colored bars, that indicate how much search volume each term receives. On the right is a list of the words that appear most frequently in the keyword suggestions.

Below this you find the relevant product section, which displays products, currently listed on Amazon, that match your keyword. By clicking on a product, you can see the exact keywords that the product currently ranks for.

Sonar does not display the complete search results online. To access the full list of keywords you have to download the CSV file by clicking “Download”. The CSV file contains all your keywords, accompanied by a search volume score from one to five (with five being the highest).

Improve your Amazon SEO!

With Sonar, Amazon Sellers sellers, vendors, and agencies can find all relevant keywords for their businesses. Increase your product listing visibility today!

Read more about Sonar

2. Scientific Seller

The next tool is Scientific Seller. This tool is perhaps unique among Amazon keyword tools, as it boasts about its lack of speed.

But you don’t have to wait for hours to get keyword results, the suggestions are available immediately. Scientific Seller will simply keep adding suggestions until you press the pause button.

So, how do you search for keywords using Scientific Seller? You start by entering one or two keywords into the search box and selecting which Amazon marketplace you want to generate keyword data for. The free plan will only allow users to generate keyword suggestions for

Then the fun starts! You’re taken through to the results page, which is split into two main columns: “Stuff Words” and “Amazon Buyer Keywords”.

Stuff Words essentially act as keywords and are accompanied, on the left-hand side, by a number which indicates how many search suggestions they feature in. If you then click that Stuff Word (for instance “golf” in the image below) you get a list of these search suggestions, which they call Amazon Buyer Keywords.

The suggestions do not have search volume scores and, whilst the figure indicating how often a Stuff Word has appeared in an Amazon Buyer Keyword does give an indication, use it as a guide only. Perhaps take a few of the Stuff Word suggestions and run Amazon PPC campaigns, to generate your own volume data.

To see the full results you need to sign up for a free account with Scientific Seller. This allows users to download results in a CSV file and also save searches, to allow them to run for a longer period.

Something to consider with Scientific Seller is that you can only conduct five searches per day. This might not seem much, but it is still 35 searches every week. This is not bad, considering you’re unlikely to be optimizing all that many PPC campaigns or altering dozens of listings at the same time. You also get a vast amount of keywords and suggestions per search, so I think the benefits of the tool outweigh that limitation.

If you need more searches, the “Seller” plan offers unlimited searches for $19.99 per month. There is also a “Power Seller” plan for $29.99 which offers unlimited searches across global Amazon marketplaces.

Scientific Seller Keyword Tool Logo

More Amazon Sales with no hard work!

Bump your monthly Amazon sales by as much as 10% with smarter keyword research software. Try Scientific Seller today!

Read more about Scientific Seller

3. Ahrefs Amazon Keyword Tool

Ahrefs offer comprehensive paid packages of tools for SEO, but they also have a free, slightly hidden-away Amazon Keyword Tool available on their website for anyone to use.

It is fairly basic, but might be exactly what you need. For each search, 100 keyword results are returned ordered by volume – an estimate of the average monthly number of searches for that keyword. You can select from a list of countries for your search, to tailor your research to the Amazon market you are interested in.

Ahrefs Screenshot

However, there is no option to download the search results, so you will have to manually record the results yourself.

Ahrefs logo

Enhance your product listings!

With over 100 million keywords theirUS Amazon database, Ahrefs’ Amazon Keyword Tool helps you Find the best keyword ideas for your Amazon listings.

Try Ahrefs Amazon Keyword Tool

4. KinWords

Finally, we come to KinWords. This is a very easy-to-use tool with built-in metrics that analyze data and present a single “KIN Score” which summarizes a keyword’s importance.

Refreshingly, this is a completely free tool, with no pushy ads or constant reminders about upgrades. It feels like a programmer’s pet project, but it is by no means clunky or basic.

For each returned keyword suggestion there are three metrics – KIN Score, Relatedness and Sales Potential. All three are out of 100 and color coded with green (high) to red (low) to indicate the relative opportunity.

Sales Potential is an assessment of the traffic potential. Relatedness is an assessment of the relevance of the keyword. These two metrics are magically combined to present the KIN Score for each keyword. So if you are doing some quick research, you only need to look at this one factor.

KinWords screenshot

You can filter out one unwanted keyword per search by typing “-” and then the word in the filter box.

You can also export the list of words and their scores to a CSV file, but must register a free account first. This is a simple process and takes only seconds to do.

Another great thing about this tool is the comprehensive tutorial videos which are accessible on the page.

KinWords logo

Go beyond traditional keyword research!

KinWords uses machine learning to discover search terms that will generate more revenue for your Amazon business  — and it’s completely free!

Try KinWords

In closing

From our research, we have found that there are only a few great free Amazon keyword research tools out there:

Besides those, the free price tracking tools Keepa and CamelCamelCamel can also be useful. It should be noted though, that both of those are designed for buyers and lack some of the more sophisticated seller features.

This post was first published in July 2017 and last updated in June 2021.



Great article.
If someone can't find actionable ideas here they aren't trying. Thank you very much


Is Sonar Free? I am asked to pay 9.90$ a month to download the app.

In reply to Joseph

Osnat, Sonar is free on their site. But you pay to have the Google Chrome extension

Dennis C
Dennis C

This is just what I've been missing all along! I can't thank you enough

Maor gabai
Maor gabai

Hi, how i can contact with sonar customer service?


Awesome share. Thanks...


highly recommend using amazeowl


These search tools are not free. I tried all of them and they are all free trials! which is the oppersite of what was said at the beginning if this article.

Andy Geldman
Andy Geldmanauthor
In reply to Andy Geldman

Hi Chris, the article is a little out of date now but only because Algopix no longer offers free research, only a free trial. The others do still have "free forever" versions.

Unicorn Smasher and Sonar are still free. Both are free because their companies also have paid tools which they promote (AMZ Tracker and Sellics respectively). But Unicorn Smasher and Sonar are definitely not free trials, because there are no paid plans to sign up to.

Scientific Seller also still has a free Amazon keyword research tool, but they also have paid plans. The free tool is not a trial, you can just use it for free.

Why did you think they were free trials? You need to avoid clicking on any promotional buttons or ads to sign up for other services, and don't upgrade to a paid plan with Scientific Seller.

Just because the service you are using is free doesn't mean that everything mentioned on those sites is also free - maybe we need to make that clearer.

Adriana Jenson
Adriana Jenson

Unicorn Smasher is no longer free. They want $49 for it and it's now called Unicorn Smasher Pro. Pro is the only available version these days.

Andy Geldman
Andy Geldmanauthor
In reply to Andy Geldman

Thanks for pointing this out, we'll add a notice to the article and update it fully in the future.

It is actually still possible to download the free Unicorn Smasher from the Chrome store (link), but it looks to have some bugs - probably not being maintained.

Leave a Reply

Your email address will not be published. Comments are subject to our Terms of Use.
Please enter the correct answer below as a way to filter out some bots.