Sitemap Scout: Open-Source XML Sitemap Health Checker (PHP + React) An open-source technical SEO tool I built that checks every URL in an XML sitemap and flags what hurts indexing: broken URLs, redirects, slow responses, duplicates, missing or stale modification dates, noindex pages, canonical mismatches and metadata issues. It comes as a PHP command-line tool and a React/TypeScript web edition at scout.ivig.dev, which exports results to CSV or JSON and runs on ordinary shared hosting. I built it from the same checks I run when auditing client sites.