Sonar Review: A Genuinely Free Amazon Keyword Tool Backed by Real Search Data

Free keyword tools often turn out to be lead-generation funnels for a paid upsell before you get any real data. Sonar is a rare exception in the Amazon tools space — a fully functional, unlimited-use keyword research tool that costs nothing, built on real Amazon shopper search queries rather than estimated or third-party data.

What Is Sonar?

Sonar is a free keyword research tool, originally from Sellics and now offered under Perpetua (the company Sellics merged with), that analyzes real Amazon search queries to help sellers discover and optimize keywords for their product listings.

Key Features

Real Amazon search data. Keyword suggestions are sourced from actual Amazon shopper search queries, not external web search data adapted for Amazon use.

ASIN reverse lookup. Enter a competitor's ASIN to discover which keywords that listing ranks for, a direct way to reverse-engineer competitive keyword strategy.

Amazon search volume calculations. Search volume estimates specific to Amazon, addressing the common gap where Amazon doesn't natively expose this data to sellers.

Kindle and e-book keyword research. Support for self-publishers researching Kindle Direct Publishing (KDP) keywords, not just physical product sellers.

Multi-marketplace support. Covers both USA and European Amazon marketplaces.

Unlimited use. No caps on searches or downloads, and no credit card required to use the free tool.

Who Sonar Is For

Sonar serves Amazon sellers and vendors looking to improve product visibility through keyword optimization and competitive analysis, at any stage — it's a genuinely useful entry point for new sellers who aren't ready to pay for a full keyword research subscription, and a solid supplementary free tool even for established sellers already using paid platforms.

Pricing

Completely free with no credit card required. Perpetua (Sonar's parent company) also offers a premium "All-in-One" platform with a 14-day trial covering additional features like PPC optimization, profit tracking, and review management, for sellers who want more than keyword research alone.

Strengths and Considerations

The fact that Sonar remains free and unlimited — rather than being sunset or paywalled after the Sellics-to-Perpetua transition — is genuinely notable and worth calling out given how many tools in this list have been discontinued or restructured over time. Because it's a lead-generation tool for Perpetua's paid platform, expect occasional prompts to upgrade, but the core keyword and ASIN reverse-lookup functionality remains fully usable without paying. As with any free tool, sellers relying heavily on Amazon keyword data for major sourcing or PPC decisions may still want to cross-reference search volume figures against a paid tool for higher-stakes decisions.

Frequently Asked Questions

Is Sonar really free, or is there a hidden paywall? It's genuinely free with unlimited use and no credit card required; a separate paid Perpetua platform exists for additional features but isn't required to use Sonar.

Does Sonar work for Kindle/KDP keyword research? Yes, it supports keyword research for Kindle and e-book listings in addition to physical products.

Which Amazon marketplaces does Sonar support? USA and European Amazon marketplaces.

Is Sonar the same as Sellics? Sonar originated from Sellics; Sellics has since merged with Perpetua, and Sonar now operates under that umbrella.

Bottom Line

Sonar remains one of the best genuinely free options for Amazon keyword research and competitor ASIN analysis — a smart first stop before paying for a more comprehensive keyword platform.