What is the best SEO audit tool?

Screaming Frog is widely used and considered the best dedicated SEO audit tool for running a thorough technical crawl, catching broken links, duplicate content, and missing tags across an entire site in one pass.

For a completely free starting point, Google Search Console covers indexing errors and crawl issues quite well, though it will not perform a full site crawl the way a dedicated desktop tool actually does.

Larger all-in-one suites like Ahrefs and Semrush bundle full auditing together with keyword research and rank tracking, genuinely worth it if you need all three combined, but overkill if you only ever need the audit piece.

Automated quality checks built directly into the publishing flow is a different approach automatic SEO software takes to the same problem.