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Publisher Rocket vs KDSPY: desktop app or browser extension?

Both tools help KDP authors research Amazon keywords, categories and competing books, and both are sold for a one-time fee. Publisher Rocket is a desktop app you open separately. KDSPY is a browser extension that works while you browse Amazon.

How we wrote this: we drafted this page with AI assistance from the vendors' official pages, fetched on 2026-10-17, then checked each fact against those pages. We did not buy or test these tools hands-on. Prices and plans are as of Oct 2026 and change; check the official site before you buy. Listings are editorial. We are not affiliated with or endorsed by any tool named here. Amazon, Kindle and KDP are trademarks of Amazon.com, Inc. or its affiliates; we are not affiliated with or endorsed by Amazon.

Quick answer

You want to research while browsing Amazon: KDSPY sits in your browser and analyzes the category, search or author page you are on.
You want a separate app with dedicated search screens: Publisher Rocket runs as a desktop app on Windows and Mac, with a Chromebook version.
You mostly need keyword lists for Amazon Ads: both offer it. Rocket has an Amazon Keywords Generator, and KDSPY says its keyword suggestions can be exported for Amazon Ads (AMS).
Price is the deciding factor: KDSPY lists the lower one-time price as of 2026-10-17, with a longer refund window.

Side by side (as of Oct 2026)

	Publisher Rocket	KDSPY
Type	Desktop app: Windows and Mac downloads; Chromebook via Google Play.	Browser extension for Chrome, Firefox, Edge, Opera and Brave on Windows, Mac, Chromebook or Linux. Does not work on iPads, tablets or phones.
Price	One-time payment of $199 for lifetime access with updates. The page also says to buy "before it becomes an annual subscription", so the model may change.	One-time fee of $79, including future updates.
Refund window	30 days.	60 days.
Devices per purchase	One device: Rocket's Terms and Conditions (section 5.1) license use on "a single device owned or controlled by You" (as of 2026-10-17).	Dual licence: up to two devices you own.
Keyword research	Keyword Search, plus an Amazon Keywords Generator for ad campaigns.	Keyword analysis with A to Z suggestions, competitor counts and estimated revenue, exportable for Amazon Ads.
Category research	Category Search. The vendor says it covers 19,000+ Amazon categories.	One-click category breakdowns. The vendor says it covers 25,000+ Kindle, book and audiobook categories and shows estimated daily sales needed to rank.
Competitor research	Competition Analyzer.	Author page analysis and daily rank tracking of any number of books over 30 days.
Other	Version 2.0.101 (Windows/Mac) and 1.0.31 (Chromebook) listed on the download page.	ChatGPT prompt templates ("KDSPY Insights"), word clouds, exports, and data from multiple Amazon country stores. Last software update listed: 12 May 2026.

The category counts are each vendor's own figures. They may count differently, so don't compare them directly.

A caution about sales and revenue estimates

Both tools show estimated sales or revenue for books and niches. These are the vendors' own estimates. They are not Amazon's own figures, and we have not checked how accurate they are. Treat them as a way to compare niches, not a forecast of what your book will earn.

Amazon also has rules on keywords that no tool overrides. KDP prohibits keywords that mention other authors, books by other authors, or sales rank, among others. See our guide to KDP categories and keywords before you paste a generated list into your book's details.

Who each suits

Publisher Rocket suits authors who like a separate research app with dedicated screens for keywords, categories, competition and ad keywords, and who use Windows, Mac or a Chromebook.

KDSPY suits authors who already spend time browsing Amazon and want numbers to appear on the page they are looking at. It also suits anyone who wants book tracking or works on two computers. It is no use on a tablet or phone.

Sources