Enter a sitemap URL to see how old your pages are according to their lastmod dates, which pages have gone longest without an update, and whether your lastmod values can be trusted at all.
Sitemap indexes are followed for up to 10 child sitemaps. WordPress sites usually have one at /wp-sitemap.xml; Yoast and Rank Math use /sitemap_index.xml.
What lastmod is and why it matters
Every URL in an XML sitemap can carry a lastmod date saying when the page last changed. Crawlers use it to decide what to fetch again. A site with accurate lastmod dates gets its updated pages recrawled sooner, and for questions where recency matters, being recrawled is the difference between an assistant quoting this year’s price and last year’s.
The catch is that crawlers only use the signal if it has proved reliable. Google has said publicly that it ignores lastmod on sites where the dates are clearly wrong. So a broken lastmod is worse than none, because it teaches the crawler to stop listening.
What the auditor checks
| Check | What a problem looks like |
|---|---|
| Coverage | More than half your URLs have no lastmod at all |
| Auto-stamping | 80 per cent or more of pages share one date, usually today’s. The CMS is writing the time the sitemap was generated, not the time each page changed |
| Age distribution | Most of the site untouched for over a year |
| Future dates | A lastmod later than today, from a timezone or scheduling error |
| Invalid dates | Values that are not in W3C date format |
| Oldest pages | The 20 URLs with the oldest lastmod, as a review list |
The auto-stamping problem
This is the finding worth the visit. Some sitemap plugins and many custom-built sites set every page’s lastmod to the moment the sitemap was built. The file looks healthy, every page appears fresh, and the signal is useless. If the auditor reports that most of your pages share a single date, check how your sitemap is generated. The fix is to take lastmod from the content’s real modified time, and to change it only when the main content changes, not when a sidebar or footer does.
What to do with the oldest pages
Old does not mean bad. Go through the list and sort each page into one of three groups.
- Still correct. Leave it alone. Do not change the date to look fresh.
- Out of date but useful. Update the facts, then let lastmod change naturally. Put a visible “last updated” date on the page as well.
- No longer needed. Remove it and redirect the URL to the closest relevant page.
Finding your sitemap
Try these in order: /sitemap.xml, /sitemap_index.xml, /wp-sitemap.xml. If none works, open /robots.txt and look for a line beginning Sitemap:. A sitemap index is followed automatically for up to 10 child sitemaps.
What this tool cannot tell you
It reads the dates in your sitemap. It does not fetch each page to check whether the content really changed on that date, so it can tell you a lastmod looks suspicious but not that an individual date is false. Files over 512 KB are cut short, and the result says so when that happens. For a large site, audit one child sitemap at a time.
Frequently asked questions
Should I update old pages just to refresh the date?
No. Changing a date without changing the content is the behaviour that makes crawlers distrust lastmod. Update a page when there is something to update.
Do changefreq and priority matter?
Google ignores both. Only lastmod is used, and only when it is accurate.
My sitemap has no lastmod. Should I add it?
Yes, if your CMS can supply the real modified date. If it can only supply the generation time, leave lastmod out.
Related
- Freshness signals: dates, dateModified and sitemaps
- IndexNow Key and Payload Helper: tell Bing about a change at once
- AI Crawler Access Checker
- All free SEO tools