Duplicate XML sitemaps: when wp-sitemap.xml and a plugin sitemap are both live

Take an inventory

Request each of the usual addresses and note what comes back:

for p in sitemap.xml sitemap_index.xml wp-sitemap.xml sitemap.xml.gz; do
  curl -s -o /dev/null -w "$p %{http_code} %{redirect_url}\n" "https://example.com/$p"
done
curl -s https://example.com/robots.txt | grep -i "^sitemap"

Then check three more places:

• Search Console → Indexing → Sitemaps. Every address ever submitted is listed, including ones from previous plugins.
• The site root over SFTP. A physical sitemap.xml file is served by the web server before WordPress loads, so it overrides any plugin sitemap at the same address.
• Bing Webmaster Tools, if you use it, which keeps its own list.

A 200 from more than one address, or more than one Sitemap: line in robots.txt, confirms the duplication.

How the lists drift apart

The WordPress core sitemap is deliberately simple. It lists public posts, pages, custom post types, taxonomy terms and author archives, up to 2,000 URLs per file. It does not read SEO plugin settings, so a page you noindexed in a plugin is still listed there, as are author archives you may have chosen not to index.

A plugin sitemap built from your SEO settings leaves those out. Submit both and Google is told to index a URL by one file and not by the other, which produces noindexed URLs in the sitemap and muddies the submitted-page counts.

A static file is worse because it is frozen at the day it was generated: deleted pages stay in it and new ones never appear.

Keep one, remove the others

1. Choose the sitemap that respects your noindex and canonical settings. With Hydrogen SEO active, that is its index at /sitemap.xml. The plugin switches the core sitemap off and redirects /wp-sitemap.xml to its own index, so old links and submissions to the core address still resolve. Nothing else is needed for the core sitemap.
2. If you are not using a plugin sitemap, the core one is fine on its own. To turn core's off manually when another generator is in charge, add add_filter( 'wp_sitemaps_enabled', '__return_false' ); to a small plugin or the theme's functions.php.
3. Delete static files. Remove sitemap.xml, sitemap.xml.gz and similar files from the site root after confirming they are not what your plugin serves. A dynamic sitemap has no file on disk.
4. Deactivate leftover generators. A standalone sitemap plugin left active after an SEO plugin was installed is a common source. Running two SEO plugins at once duplicates meta tags too; see fixing duplicate meta output.
5. Clean robots.txt. It should contain one Sitemap: line, pointing at the index you kept. Hydrogen SEO adds its own line automatically; remove hand-written ones for retired addresses. A physical robots.txt file must be edited by hand.
6. Clean Search Console. In the Sitemaps report, open each obsolete entry and choose Remove sitemap, then submit the surviving index once.

Multiple sitemaps that are fine

Do not merge sitemaps that cover different things. A sitemap index with child sitemaps per post type is one sitemap, not many. Separate news and video sitemaps are meant to sit alongside the main one. A multilingual site may have one index per language, and a site with a blog on a subdomain needs a sitemap per host. The problem this page describes is two generators describing the same pages.

Check the result

Run the inventory loop again. One address should return 200 and the others a redirect to it or a 404. robots.txt should show a single Sitemap: line. Validate the surviving file with our XML sitemap validator, and run the free SEO audit, which reads the sitemap named in robots.txt and reports whether it parses and how many URLs it lists.