Why does my sitemap.xml return HTML instead of CSV?

If you visit /sitemap.xml and see a webpage instead of XML, your framework or hosting layer is serving the app shell at that path. It's common with single-page React/Vue/Angular apps, Next.js sites missing a sitemap route, or Vercel/Netlify rewrites that catch everything. Result: when you paste that URL into a converter, the converter receives HTML, not XML, and either errors or extracts every internal link from the page (sometimes useful, sometimes not). Two fixes. First: switch the converter to HTML sitemap mode — xmlsitemapmaker.com auto-detects this and falls back to extracting <a href> links. Second: fix the framework so /sitemap.xml returns Content-Type: application/xml with real XML content.