Sitemap freshness (lastmod)

<lastmod> lets an agent re-read only what changed instead of recrawling everything.

Category: Discoverability
Standard: Recommended

What it checks

The extension fetches the first sitemap declared in robots.txt that is on the same site, or /sitemap.xml if none is declared. A sitemap hosted on another domain is not fetched. It counts the <url> and <sitemap> entries and how many of them carry a <lastmod> date. For a sitemap index, it counts the entries in the index itself; it does not open the child sitemaps.

Results

Status	When
Pass	Every entry in the sitemap has a `<lastmod>`
Warn	Some entries have a `<lastmod>` and some do not
Warn	No entry has a `<lastmod>`
N/A	No sitemap was found to inspect
N/A	`robots.txt` only lists sitemaps on other hosts

This is a bonus check: complete <lastmod> dates add points, and missing ones cannot lower the Discoverability score.

How to fix

Add a <lastmod> to each entry, set to the date the page’s content last changed in W3C Datetime format. Most CMS and static-site sitemap plugins can do this for you.

<url>
  <loc>https://example.com/pricing</loc>
  <lastmod>2026-09-01</lastmod>
</url>

Keep the dates honest. A <lastmod> that changes on every build tells an agent everything changed, which is no better than having none.