A premium or free Amazon keyword tool is a must for all self-publishing authors.
Search keywords on Amazon help customers find your book when they use search terms to find a new book to read.
But discovering relevant keywords for your book is not a quick and easy process. To uncover what search queries Amazon customers use, you need to use a tool to find keyword suggestions.
A book or ebook is like all other Amazon product listings. The way to succeed is by optimizing your product and Amazon page with backend keywords.
What are backend Amazon keywords?
When you publish a book on Amazon KDP, you need to add seven keywords.
These should be long-tail keywords of at least three or four words.
However, after you publish, you will not see these keywords in your product description or Amazon sales page.
They will only appear when a customer does a product search. This is why they are often called hidden or Amazon backend keywords.
You can try a quick Amazon keyword search to see how Amazon autocomplete displays a list of keyword suggestions for buyers.
You can use this feature as a quick, basic Amazon and KDP keyword tool.
However, you can only access ten Amazon keyword suggestions at a time, and there is no information about Amazon search results volume.
To access more details and data, you need to use a dedicated tool.
So what are the best options for doing Amazon keyword research for a self-publishing author?
Five Amazon Keyword Tools
Yes, you can use Google search or the Google keyword planner to find ideas for your keywords.
But the results will be general and more related to how search engines rank keywords rather than how Amazon SEO works.
It is better if you use an Amazon keyword search tool that is specifically going to deliver results from the Amazon database.
For the best results, though, you need to use a tool that accesses only the database for books and ebooks.
Of course, as with all software and online tools, there are free and premium choices.
1. Publisher Rocket (Premium Only)
I have to start with the best.
Publisher Rocket is by far the most popular keyword tool for Amazon authors.
It gives you access to the entire Amazon database for book and ebook keywords as well as categories. On top of that, you can research Amazon PPC keywords.
To start a search, all you need to do is enter a seed keyword. The software will deliver a long list of keyword suggestions for you.
I truncated the image above because the list was too long to post here. But as you can see, along with all the data, you can investigate each keyword idea relative to competitors.
You can find data relating to sales volume, publishing age, and search volume. In other words, all the data you need to find the best possible keywords for your book.
Not only can you discover great keywords, but you can also find the best categories for your book.
If you want one tool that gives you unrestricted access to as much data as you want, Publisher Rocket is the best choice.
Yes, it is a premium software tool. But unlike most, it is not a subscription service. You only pay one time for the software, and it is continuously updated for free.
2. Sonar (Free and Premium)
Sonar is a terrific free keyword tool for Amazon keywords. While it is not specific to books, it doesn’t do a bad job at all.
I completed multiple searches with Sonar, and I couldn’t find any restrictions. Another good thing was that it didn’t ask for my email address.
The results are useful.
The left panel delivers a long list of ideas. On the right, all the frequent words are clickable to give you more ideas.
While it is a tool for any Amazon seller, it is probably the best free Publisher Rocket alternative. It’s an Amazon keyword research tool option that will work for authors.
3. KDT Amazon Keyword Tool (Free and Premium)
The KDT Keyword tool is a little restricted. But it has a few upsides.
While the free version restricts you to only two searches per day, you can filter the results in many ways.
You can also select the Amazon marketplace or country you prefer.
The results are not specific to books. But from the long list of suggestions you get from your seed keyword, you can select possible new keywords to suit your book title.
There is a premium version. But because the app delivers mostly keywords for general product pages, it might not be a good investment for authors.
4. Keyword Tool (Free and Premium)
Keyword Tool is an allrounder. You need to choose Amazon, but you have many other choices.
The advantage of this app is that you can select Amazon and then also books. It delivers a long list of keyword ideas for you.
While it blocks search volume, trend, and CPC data, the free version gives you plenty to work with for your research.
On the plus side, though, you are getting data related only to books and ebooks, and you can select by language or region.
For a free tool, it is worth investigating to help you find keywords for your Amazon listing.
5. SellerApp (Free and Premium)
SellerApp is another option for you to access Amazon’s database.
It has a limit of only ten results per search. But the advantage is that it provides you with search data.
The best use for this app is to find your potential keywords by using an Amazon search or another app. Then enter it into this app to get some search data.
There is also a Chrome extension available.
I haven’t tried the extension, so I can’t give you any feedback on how well it works. But if you are familiar with Chrome extensions, you might want to give it a try.
If you are self-publishing books and ebooks, you have to know about choosing Amazon keywords.
You will definitely need to use tools to find the best ones for your titles.
Should you use a free tool or premium software?
The choice is up to you. If you have published one or two titles, the best free Amazon keyword tool is probably Sonar, and it should do enough for you.
But if you have more titles or you are struggling for sales, a premium app like Publisher Rocket might be a better option for you.