Free SEO audit tool and tag checkers

Marlo checks the basics every page needs: the title, description, headings, canonical and social tags. Paste a URL to run all of them at once, or read how each one works below.

Free. No signup. Open source.

• Canonical tag checker

  Free canonical URL checker: see if your page has a canonical tag, what it should say and how to add it. No signup, open source.

• Open Graph tags checker

  Free Open Graph tag checker: test og:title, og:description and og:image and see how to fix missing ones. No signup.

• Meta description checker

  Free meta description checker: find a missing description or one over 160 characters. Paste a URL, no signup, open source.

• H1 tag checker

  Check your page for a missing H1 or multiple H1 tags and see how to fix the heading structure. Free, no signup.

• llms.txt generator

  Build an llms.txt file for your site from a name, a summary and a list of links. Made in your browser, free, no signup.