XML sitemap

An XML sitemap is a machine-readable file that lists the URLs a site owner wants search engines to know about, often with metadata like last-modified dates. It helps crawlers discover pages efficiently, especially ones that internal linking reaches poorly. A sitemap aids discovery and prioritization; it does not guarantee that a listed URL will be crawled or indexed.

How it works

Each sitemap lists canonical, indexable URLs and can include a lastmod timestamp signaling when a page changed. A single file holds up to 50,000 URLs or 50 MB uncompressed; larger sites split into multiple sitemaps referenced by a sitemap index. You submit the sitemap in Google Search Console and reference it from robots.txt. The most useful sitemaps are clean: only 200-status, canonical, indexable pages — no redirects, no noindex, no blocked URLs. Accurate lastmod values help engines recrawl updated pages sooner, but only if they are trustworthy; engines learn to ignore timestamps that always claim “today.”

Where it applies

Sitemaps pay off most where discovery is hard or scale is high.

• Ecommerce — large, frequently changing catalogs rely on sitemaps to surface new and updated SKUs quickly.
• Publishing — news sitemaps expedite discovery of time-sensitive articles.
• Enterprise — deep sites with weak internal linking use sitemaps to expose orphaned but valuable pages.
• Marketplaces — automated sitemap generation keeps pace with listings created faster than editors can link them.

What matters from each seat

• In-house — treat the sitemap as a curated index of what should rank, and compare submitted-versus-indexed counts in Search Console to spot coverage gaps.
• Agency and consulting — a dirty sitemap full of redirects and noindex URLs is a common, quick-fix diagnostic on new clients.
• Engineering — generate sitemaps dynamically from the canonical URL set, segment them logically, and keep lastmod honest.