Google, sitemaps and images
Should I put my images into my sitemap? Will it help get my images in to Google?. This was a question a friend and I were recently asking ourselves. Unfortunately a lot of people who think that they know what they are talking about are posting 'yes' in forums, but after a little analysis the answer became clear.
Google does not mention putting images in sitemaps
First of all look at Google's own wording in its Webmaster Tools. Its fairly obvious from this what Google thinks a site map is for, and images are not mentioned here or in Google's further explanation of sitemaps:
"Submit a Sitemap to tell Google about pages on your site we might not otherwise discover."
Google needs the page to associate keywords with the image
Secondly think about how Google associates words with images so they can found in its search. Google uses:
- words close to the image in the page it appears in
- words in the tags (eg. alt and tag) for the img from the page it appears in
- words from the image name
If you were place images in your sitemap how would Google find this useful? It could not determine the first two pieces of information and would be left with purely the image name. How would Google know the page the image appears in from just the image URL?
Google Guide actually tells us how its image search works and its clear Google uses information from the page the image appears in:
"The words “Larry Page” and “Sergey Brin” appear near images of Eric Schmidt, or in image captions, or in links to those images. Google makes a guess that the words are related to the image. Google technology isn’t yet to the point where it can tell what’s in an image by looking at it directly."
Images are already part of the pages in your sitemap
The final clincher is this. If you've already provided your pages in your sitemap - do you really think Google is going to ignore the images in that page? So why put them in your sitemap?
Update 11th Aug 2008
I just found this little Gem in Google Webmaster Tools
"The stats on the Sitemap Details page are a close approximation of the status of your URLs. We don't guarantee that our system will index all the URLs in a Sitemap, and it's normal for some pages not to be indexed. In addition, we don't index images directly (instead, we index the page that contains the image). As a result, direct image URLs in your Sitemap won't be indexed."