Niche Hound

Niche Hound is a free Chrome extension for Amazon book niche research. You search Amazon.com as usual, and it adds sales rank, estimated sales and estimated author royalties under each result, plus a summary of the whole search at the top. It launched in mid-September 2026 (version 1.0.0), so it is very new and has almost no track record yet.

What You Get#

• Per-book details: Best Sellers Rank for every edition (Kindle, paperback and hardcover) plus the best category rank, publisher, Kindle Unlimited status, first publish date and page count.
• Sales and royalty ranges: Estimated monthly sales, added up across editions, and estimated author royalty for independently published books using KDP's US royalty and printing-cost rules. Figures are shown as ranges, not single numbers.
• Search summary: A 0–100 opportunity score based on how well the top results sell and how many reviews they have, with median best rank, typical sales, median price and median reviews. It also counts how many top books are indie-published and how many are in Kindle Unlimited.
• Expand keywords: Pulls Amazon's own search-suggestion (autocomplete) terms for your keyword, which you can copy or download as a CSV file for titles, subtitles and the seven KDP keyword slots.
• Free web calculators: A BSR-to-sales calculator and a KDP royalty calculator (with a Kindle Unlimited page-read estimator) on getnichehound.com. Neither needs the extension or a sign-up.

Who It's For#

• KDP authors on a zero budget: Useful for sizing up a genre or sub-niche before writing, with nothing to install beyond the extension.
• Low-content and nonfiction publishers: The indie-vs-traditional count and the royalty estimates show quickly whether self-published books can compete in a search.

Pricing: Free, with no account and no ads. The privacy policy (effective September 13, 2026) mentions that a paid plan could be added later, but none exists yet.

Strengths#

• Clear about its estimates: The site names its method. It uses two public rank-to-sales models (BookBloom's banded model and a common rank-calculator curve), shows the spread between them as a range, and scales print sales against Kindle at the same rank (paperback about 30%, hardcover 15–30%).
• Every edition in one place: Niche Hound loads the product pages for each result's other editions and adds up their estimated sales.
• Privacy: According to its privacy policy and Chrome Web Store disclosure, it runs only on Amazon.com, has no analytics or tracking, sends Amazon requests from your own browser, and keeps results in local storage for up to 12 hours.

Limitations#

• Amazon.com only: No UK, German, Canadian or other marketplaces. Sales and royalty estimates cover books only.
• No search volume: Expand keywords lists Amazon autocomplete suggestions. It does not estimate how often each term is searched.
• Estimates leave out Kindle Unlimited income: Page-read earnings are not included in the per-book royalty figures, which undercounts KU-heavy genres.
• No track record: As of September 29, 2026, the Chrome Web Store listing shows 12 users, no ratings, and version 1.0.0 updated September 18, 2026. The first Wayback Machine capture of the site is from September 14, 2026. The developer, "Hound & Raven Tools" (which also makes the Page Raven send-to-Kindle extension), has not identified itself as a trader, so EU consumer rights do not apply.
• Depends on Amazon's page layout: Like any tool that reads Amazon pages, it can break when Amazon changes its HTML. The developer says the extension downloads updated page-reading rules so it can be fixed without a new release.

Alternatives#

KDP Miner is the closest free substitute. It has been around longer, works on Audible and 11 Amazon stores, and adds batch keyword analysis, but it gives no sales or royalty estimates. For keyword search-volume estimates and category research, Publisher Rocket ($199 one-time) is the usual paid pick. KDSpy offers paid revenue estimates across more Kindle stores.