What is XML sitemap?
An XML sitemap is a file listing the URLs on a site that you want search engines to crawl, along with when each was last changed, submitted through Search Console so new and updated pages are found quickly.
Also called: sitemap.xml, sitemap.
A sitemap does not make pages rank. It makes them discoverable, which is a smaller claim and a real one — especially for a new site with almost no inbound links, or a site that publishes often. Without one, discovery depends on crawlers stumbling across links.
The most useful field is lastmod. Set honestly, it tells a crawler which pages are worth revisiting, and updated content gets re-indexed in days rather than weeks. Set to "today" on every page as some plugins do, it becomes noise and gets ignored.
Only include pages you actually want indexed: canonical URLs, HTTP 200, not blocked by robots.txt, not noindexed. A sitemap full of redirects and dead ends erodes the trust you are trying to build.
What to actually do about it
- Serve it at /sitemap.xml and reference it from robots.txt.
- Include only canonical, indexable URLs.
- Set lastmod from the real modification date.
- Submit it once in Search Console; it is re-read automatically after that.
- Split into multiple sitemaps once you pass 50,000 URLs.
Koo generates and updates sitemap.xml for every site as pages and posts change, references it from robots.txt, and pings the search engines when something new publishes.
Related terms
robots.txt
robots.txt is a plain-text file at a site's root that tells crawlers which paths they may or may not request. It controls crawling, not indexing, and it is a public request rather than a security measure.
Canonical URL
A canonical URL is the single address you declare as the official version of a page, using a rel="canonical" tag, so search engines consolidate ranking signals on one URL instead of splitting them across near-identical copies.
llms.txt
llms.txt is a plain-text file at the root of a website that gives AI assistants a curated, markdown-formatted map of its most important pages, so a model can find the substance without crawling and parsing the whole site.