Skip to content
Browse all guides

Issue #157 · important

Issue 157

What is this issue?

This issue checks whether a website has a dedicated image sitemap that helps search engines discover and index images that may not be found through normal crawling.

A passing implementation means:

  • An image sitemap exists at a standard location (e.g., /image-sitemap.xml or /sitemap-images.xml)
  • The sitemap is properly formatted with <image:image> entries
  • Images are listed with required metadata (URL, optionally title, caption, license)
  • The image sitemap is referenced in the main sitemap or robots.txt

Example:

<?xml version="1.0" encoding="UTF-8"?>
<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/page1</loc>
    <image:image>
      <image:loc>https://example.com/images/photo.jpg</image:loc>
      <image:title>Product Photo</image:title>
      <image:caption>Front view of product</image:caption>
    </image:image>
  </url>
</urlset>

Why does it matter?

Image Discovery: Search engines may not discover images that are loaded via JavaScript, CSS backgrounds, or lazy loading. An image sitemap ensures all images are found.

Image SEO: Images can drive significant traffic through Google Images search. A sitemap increases the chances of images being indexed and ranked.

Crawl Budget Optimization: Images embedded deep in the site structure or behind interactions may not be crawled. A sitemap provides a direct path for discovery.

Rich Results Eligibility: Properly indexed images can appear in Google Images and may enhance regular search results with thumbnail previews.

SEO Health Score: Having an image sitemap improves the technical SEO score by demonstrating comprehensive content discovery optimization.

How to fix it

  1. Create an image sitemap - Generate an XML sitemap specifically for images following the image sitemap schema.

  2. Include all important images - Add images that are valuable for SEO (product photos, infographics, illustrations) but may not be easily discoverable.

  3. Add optional metadata - Include <image:title>, <image:caption>, and <image:license> where relevant to provide context.

  4. Submit the sitemap - Add the image sitemap URL to:

    • Google Search Console
    • Your main sitemap index file (if using one)
    • The Sitemap: directive in robots.txt

  5. Keep it updated - Ensure the sitemap is regenerated when new images are added or old ones removed.

  6. Validate the format - Use Google Search Console's sitemap testing tool to verify the sitemap is properly formatted.

Examples

Example 1: Basic Image Sitemap

Problematic State (Fails): No image sitemap exists. Images are only discoverable through crawling HTML pages.

Corrected State (Passes): Create an image sitemap at /image-sitemap.xml:

<?xml version="1.0" encoding="UTF-8"?>
<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/products</loc>
    <image:image>
      <image:loc>https://example.com/images/product1.jpg</image:loc>
      <image:title>Product 1</image:title>
    </image:image>
  </url>
</urlset>

Example 2: Missing Sitemap Declaration

Problematic State (Fails): An image sitemap exists at /image-sitemap.xml but is not declared in robots.txt.

Corrected State (Passes): Add the sitemap to robots.txt:

User-agent: *
Disallow: /admin/

Sitemap: https://example.com/sitemap.xml
Sitemap: https://example.com/image-sitemap.xml

Example 3: Images Not Discoverable via HTML

Problematic State (Fails): Images are loaded via JavaScript and not present in the initial HTML:

<div id="product-images"></div>
<script>
  // Images loaded dynamically via JavaScript
</script>

Corrected State (Passes): Create an image sitemap to ensure these images are discovered:

<url>
  <loc>https://example.com/products</loc>
  <image:image>
    <image:loc>https://example.com/images/product1.jpg</image:loc>
  </image:image>
</url>

How PixyScan detects this

PixyScan performs the following checks:

  1. Sitemap Discovery: PixyScan looks for image sitemaps by:

    • Checking robots.txt for Sitemap: directives pointing to image sitemaps
    • Trying common paths like /image-sitemap.xml, /sitemap-images.xml
    • Checking if the main sitemap references image sitemaps

  2. Sitemap Validation: If an image sitemap is found, PixyScan validates:

    • The XML is properly formatted
    • The <image:image> entries are correctly structured
    • Image URLs are absolute and accessible
    • Required namespaces are declared

  3. Image Coverage: PixyScan checks if important images on your site are included in the image sitemap.

  4. Issue Identification: PixyScan raises issues when:

    • No image sitemap is discovered (SUGGESTION)
    • The image sitemap is not declared in robots.txt (SUGGESTION)
    • Image URLs in the sitemap return errors (WARNING)
    • The sitemap format is invalid (CRITICAL)

References