Paste your page URLs, set sensible priorities, and download a protocol-perfect sitemap.xml.
A sitemap is the list you hand search engines so nothing important depends on being discovered by luck. This generator takes your URL list, from your CMS export, your site's navigation, or typed by hand, validates and cleans it (trimming blanks, deduplicating, flagging lines that are not URLs), and emits protocol-correct XML: homepage at priority 1.0, standard pages at 0.8, deeper pages at 0.64 by path depth, with your chosen change frequency and last-modified date throughout. The result is ready to upload as /sitemap.xml and submit in Search Console and Bing Webmaster Tools.
What it deliberately does not do: crawl your site. Web pages cannot crawl arbitrary sites (browser security blocks reading other sites' pages), and a sitemap built from a partial crawl is worse than one built from your own page list, which is complete by definition. Keep the sitemap honest, only canonical, indexable, live URLs belong in it; a sitemap listing redirects and 404s teaches engines to ignore it. One file holds up to 50,000 URLs; beyond that, split by site section.
Does every site need a sitemap? Small sites with clean internal linking get crawled fine without one. The moment a site has pages that matter and are more than a few clicks deep, or launches content that should index fast, a sitemap earns its keep.
Do priority values affect rankings? No, priorities are relative hints within your own site about crawl attention, not ranking boosts. Google largely ignores changefreq; Bing reads both. Honest values are the policy.
Where does sitemap.xml live? At the domain root, referenced from robots.txt with a Sitemap: line (the generator on this site adds it) and submitted in the search consoles.