Sitemap checker — validate any XML sitemap

Quick answer: paste a sitemap URL, or just a domain, and this fetches the XML and checks URL count, lastmod coverage, size headroom and whether it is an index pointing at further files.

What a sitemap is and is not

A sitemap is a discovery aid. It tells a search engine which URLs exist and, where the dates are trustworthy, which have changed. It does not oblige anything to crawl them, keep them, or rank them.

That distinction decides what to do when Search Console reports most of your URLs as discovered, currently not indexed. That message means discovery worked. The sitemap did its job and the problem is elsewhere: usually that the domain has not earned enough crawl allocation for its page count. Adding URLs in that situation makes the ratio worse, not better.

The limits, and what happens at them

Fifty thousand URLs and fifty megabytes uncompressed per file. Cross either and the file is rejected, not truncated — a failure mode worth knowing, because it turns gradual growth into a cliff. A sitemap index solves it by pointing at multiple files, which is what Shopify does out of the box.

lastmod is worth having only if it is true

Google has said it uses lastmod where a site values are consistently accurate, and disregards it where they are not. A site that stamps every URL with today teaches the crawler to ignore the field, and then cannot use it when something genuinely changes.

If your platform cannot emit a real modification date, omit the field. An absent lastmod costs nothing; a dishonest one costs the signal.

What belongs in it

Every URL you want indexed, and nothing else. Redirects, noindexed pages, 404s and filtered variants send contradictory instructions and spend crawl on URLs you have already decided against.

On Shopify the file is generated for you as an index over products, collections, pages and blogs. You control its contents indirectly, through publishing state and whatever the theme marks noindex — Shopify sitemap covers where each of those lives.

If the sitemap does not answer at all, check the path before the file: the redirect checker shows whether it is answering directly or being sent somewhere that has none.