Which parts of your sitemap Google ignores
Most sitemap checkers tell you whether the XML is valid. Valid is easy, and it is almost never why a sitemap is not doing its job.
This one tells you which of the fields you wrote Google actually reads. Two of the three optional ones it does not read at all, and the third is only used when it can be checked against the page.
The sentence this is built on
It is one line of Google’s own documentation, and it retires two fields that most sitemap generators still write:
Google ignores <priority> and <changefreq> values. Google uses the <lastmod> value if it’s consistently and verifiably (for example by comparing to the last modification of the page) accurate.
Read the last word carefully. Verifiably is why a lastmod stamped with the time the file was generated is worse than no lastmod at all: it is the one field Google uses, filled with a date it can disprove by looking at the page.
Which is why this tool flags a sitemap whose every entry shares one date. That is not a per-page modification time. It is a build timestamp wearing one.
What it does and does not do
- Nothing you paste leaves this page
- The check runs in your browser. There is no request, so there is nothing to log and nothing on our side that ever sees your file. The network tab will show you that pressing the button makes no request at all.
- It reads the file, not your site
- It cannot tell you whether the URLs in it return 200, whether those pages are indexed, or whether anything is missing from the list. It reads what you pasted.
- The parser is the one our crawler obeys
- Not a second implementation written for a marketing page. Two copies agree until somebody fixes a bug in one of them, and then this explains a file differently from the crawler that reads it for real.
- An ignored field is not an error
- A priority of 0.8 is valid, and it does nothing. Those are reported separately from the things that are actually wrong, because calling a harmless field an error is how a report stops being read.
What this product does with sitemaps
ShownTrue follows a site’s sitemap when it crawls, and its own sitemap carries a lastmod per page derived from the commit that last changed that page, rather than the time the file was written. That is the distinction this tool is about, applied to ourselves.
The crawler works and has crawled this site over the real internet. No customer has ever run one, so there are no results here about anybody’s site.