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Ahrefs Free vs Semrush Site Audit: catalog facts
Ahrefs Free	Semrush Site Audit
Freemium Free for verified websites; paid Ahrefs plans add more tools and data.	Freemium A limited free crawl is available; larger audits require a paid Semrush plan.
Web, Browser extension	Web
Technical site audit at no cost Backlink and keyword ranking data from Ahrefs' index	Issues ranked by severity with fix suggestions Covers AI search visibility as well as classic SEO
Requires an account and site ownership verification Full data for other people's sites needs a paid plan	The free crawl is limited Full use requires a paid Semrush subscription
Web application, Browser extension	Web application
Closed source	Closed source
License not stated	License not stated
Account needed	Not stated if an account is needed
Needs internet	Needs internet
Official website Full listing and sources Checked September 23, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.