Google’s John Mueller cautions site owners that a change to image URLs will affect how they rank in image search results.
This is particularly relevant to sites that get a lot of traffic from Google Images.
Changing an image URL, even though it’s the same image appearing on the same page, will result in Google treating it as a new image.
So it will have to be recrawled, reprocessed, reindexed, and work its way up the rankings again.
That could take a long time, as Mueller notes, because images are not crawled as often as web pages.
The topic of image search rankings came up during a recent Google Webmaster Central hangout where the following question was submitted:
“We’ll have a technical change in our shop that will change all of our image URLs… Does Google know that this is the same picture? Or will we lose rankings? Should we set up redirects for image URLs?”
Mueller responded with an emphatic “yes.”
Changing image URLs will absolutely affect how those images rank.
However, the damage can be mitigated by setting up redirects.
Redirecting old image URLs to new URLs will forward ranking signals from the old images to the new ones.
Using redirects is a “fantastic” way to deal with the situation, Mueller says.
Avoid changing image URLs it at all possible. But, if it has to be done, make sure redirects are in place.
You can hear the full question and answer in the video below, starting at the 17-minute mark.
“Yes, this will affect your website in Google Images in the image search. In particular, if we see changes in URLs with regards to embedded images then that’s something where we will have to go off and first recrawl those images, reprocess them, reindex them, and get them all ready for image search again.
So if you just change the URLs that are referenced within your pages then that will result in those images being seen as new images. And with regards to your ranking they will kind of have to work their way up again.
So setting up redirects, like you mentioned, that’s a fantastic way to do that. Because that way we know the old images are related to the new ones and we can forward any signals we have from the old ones to the new images. So that’s really what you should be aiming for there.
This is particularly relevant if a site gets a lot of traffic from image search. And it’s something where image search is a little bit different from web search, in that with images we find that images tend not to change as much so we don’t crawl them as frequently.
So if you make significant changes in the image URL structure that you’re using it’s going to take a lot longer for us to reprocess them.
So, in particular for images, you really need to make sure that those redirects are set up. And that’s something that often times you don’t see directly because you load the page, it refers to those new image URLs, and you don’t realize that actually those redirects between the old image URLs and the new image URLs is missing.
So, if you get a significant amount of traffic from Google Images, make sure to have those details covered.”