Sitemap lastmod Guide
The <lastmod> field signals when a URL meaningfully changed. Accurate values help recrawl prioritization; fake ones erode trust.
What good looks like
- lastmod reflects a real content change, not the build time of every page.
- Derived from a source of truth (e.g. the last git commit that touched the file).
- Present on each URL entry.
Common mistakes
- Setting today's date on every URL each build.
- Omitting lastmod entirely.
- lastmod that disagrees with the actual page.
Verify
Inspect coverage with the Sitemap Validator. Background: optimizing sitemap.xml.
FAQ
Does lastmod guarantee a recrawl?
No. It is a hint used alongside other signals, not a command.
Should every page have today's date?
No — that signals nothing. Use the real last-change date.