image sitemap

Google finds most images by crawling standard <img> tags on your pages, so an image sitemap is a supplement, not a replacement. It earns its keep when images are hard to reach: rendered by JavaScript, served from a separate media or CDN domain, or hidden behind galleries and lazy-loading a crawler may not trigger.

How the syntax works

Image tags nest inside each page’s <url> entry, and you declare the namespace on the <urlset>:

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
        xmlns:image="http://www.google.com/schemas/sitemap-image/1.1">
  <url>
    <loc>https://example.com/product/</loc>
    <image:image>
      <image:loc>https://cdn.example.com/photo.jpg</image:loc>
    </image:image>
  </url>
</urlset>

Each <url> can hold up to 1,000 <image:image> entries. Cross-domain image URLs are allowed here (unlike regular sitemaps) as long as both the page domain and the image or CDN domain are verified in Search Console and robots.txt permits crawling.

One thing that trips people up: the older <image:caption>, <image:title>, <image:geo_location>, and <image:license> tags are no longer supported, so <image:loc> is effectively the only tag that still does anything. Alt text and captions belong in the page HTML, not the sitemap. Because it is a plain sitemap extension, all the usual sitemap rules apply (valid XML, submitted in Search Console or referenced in robots.txt).