Free robots.txt & Sitemap Validator vs Screaming Frog SEO Spider
Quick answer
Fetches and validates a site's live robots.txt and sitemap.xml instantly in the browser. Screaming Frog SEO Spider is different in scope — desktop site-crawling software (free tier + paid license). Neither is trying to fully replace the other.
Free robots.txt & Sitemap Validator
Fetches and validates a site's live robots.txt and sitemap.xml instantly in the browser.
Use it when: You want a quick check that these two files are valid and reachable.
Screaming Frog SEO Spider
Crawls an entire site link by link, checking robots.txt compliance, redirects, broken links, and far more — a full desktop crawler, not a single-check tool.
Use it when: You need to crawl and audit every URL on a site, not just validate two files.