Crawl a site and build a valid XML sitemap containing only the URLs that should actually be in one.
What Gets Included
The generator crawls the site and then filters, which is the part most sitemap plugins skip. A URL belongs in a sitemap only if it returns 200, is canonical to itself, is not blocked from indexing, and is a page you would want someone to land on.
Plugins that include every URL a CMS can produce generate sitemaps full of tag archives, paginated listings and pages carrying a noindex directive. A sitemap contradicting your own directives is a confusing signal, not a helpful one.
Reading the Output
Generator output, one site
CRAWLED 412 URLs
INCLUDED 318
EXCLUDED 94
noindex directive 14
non-canonical 31
redirects 22
404 22
paginated archives 5
OUTPUT sitemap_index.xml
3 child sitemaps, 5,000 URL cap each
LASTMOD from server response, not build timeNinety-four excluded URLs out of 412 is ordinary, and every exclusion is a URL that would have weakened the file. The lastmod line matters more than it looks: a sitemap that stamps every URL with today's date each time it rebuilds is telling search engines the entire site changed, which teaches them to ignore the field.
Questions
Do I need one if my CMS makes one?
Only if the generated one is wrong, which is worth checking before assuming. Many include URLs that should not be there.
Does a sitemap help pages get indexed?
It helps them get discovered. Indexing is a separate decision the search engine makes.
What does it cost?
It runs on credits, not a subscription, and credits never expire.
Build one for a site you know well and read what got excluded. That list is usually more interesting than the sitemap.
Runs on credits · No subscription · Credits never expire