Short answer: not always. Google's documentation says a small site that's well linked internally may not need a sitemap at all. But for most business websites, one is cheap to set up and removes doubt, so it's usually worth having.

The more useful question is what a sitemap can and can't do, because a lot of sitemap advice is built on tags Google doesn't use.

What does a sitemap actually do?

A sitemap is a file that lists the URLs you want search engines to know about, usually with the date each page last changed. It helps Google discover pages, especially ones that are hard to reach by following links.

What it doesn't do is guarantee anything. Google describes sitemaps as a hint: listing a URL doesn't force it to be crawled or indexed, and leaving one out doesn't stop it being found through links.

When might you not need one?

Google says you might not need a sitemap if your site is:

  1. Small, around 500 pages or fewer that you want in search results.
  2. Comprehensively linked internally, so Google can reach every important page from the home page.
  3. Light on media and news content that you want to appear in image, video or news results.

Plenty of small business sites meet all three. Even so, a sitemap does no harm, and most platforms generate one automatically.

When does a sitemap really help?

  • Large sites, where some pages are many clicks deep.
  • New sites with few links from other websites yet.
  • Sites that change often, where accurate last-modified dates help Google decide what to recrawl.
  • Pages that are poorly linked, such as archive or filtered pages you still want indexed.

Which sitemap tags does Google ignore?

This is where most advice goes wrong.

priority and changefreq

Google says it ignores both. Setting your home page to priority 1.0 and "daily" changes nothing in Google Search.

lastmod

Google does use lastmod, but only when it's consistently accurate. If every URL shows today's date on every request, the signal becomes useless. Only change it when the page's main content actually changes.

How big can a sitemap be?

One sitemap file can hold up to 50,000 URLs or 50MB uncompressed, whichever comes first. Bigger sites split their URLs across several files and list them in a sitemap index.

How do you submit a sitemap?

There are two standard ways, and you can use both:

  1. Search Console: add it in the Sitemaps report. You'll see when Google last read it and whether it found errors.
  2. robots.txt: add a line such as Sitemap: https://www.example.com/sitemap.xml. Any search engine that reads your robots.txt can then find it.

Google retired its old "ping" endpoint for sitemaps in 2023, so tools that still ping it aren't doing anything useful.

A quick sitemap checklist

  • Only list canonical URLs that return a 200 status and aren't set to noindex.
  • Use full, absolute URLs in the same format as your canonicals.
  • Keep lastmod honest.
  • Check the Sitemaps and Pages reports in Search Console after big changes.

The bottom line

A sitemap won't make pages rank, and a tiny, well-linked site can live without one. For everyone else it's a low-effort way to help search engines find the right URLs, as long as it lists clean, canonical pages with honest dates.