Image URLs changed 3 times after using a CDN - How to Handle for SEO?

[emerald]

Hi Mozzers,
Hoping for your advice on how to handle the SEO effects an image URL change, that changed 3 times, during the course of setting up a CDN over a month period, as follows:

• (URL 1) - Original image URL before CDN:www.mydomain.com/images/abc.jpg
• (URL 2) - First CDN URL (without CNAME alias - using WPEngine & their own CDN):
  username.net-dns.com/images/abc.jpg
• (URL 3) - Second CDN URL (with CNAME alias - applied 3 weeks later):
  cdn.mydomain.com/images/abc.jpg

When we changed to URL 2, our image rankings in the Moz Tool Pro Rankings dropped from 80% to 5% (the one with the little photo icons).

So my questions for recovery are:

• Do I need to add a 301 redirect/Canonical tag from the old image URL 1 & 2 to URL 3 or something else?
• Do I need to change my image sitemap to use cdn.mydomain.com/images/abc.jpg instead of www.?

Thanks in advance for your advice.

[RyanPurkey]

You're on it. Redirecting to the new image source and submitting a new sitemap pointing to the URL 3 location for your images will be big steps in the right direction.  Be sure to follow the instructions here for your sitemap: https://support.google.com/webmasters/answer/178636 as well as reviewing image publishing guidelines: https://support.google.com/webmasters/answer/114016. Cheers!

[emerald]

Hi Ryan,
Thanks for your reply and advice. I've read the guidelines and will follow those. But I wonder if you can clarify an issue on implementing them that is not answered there:

On my site the images in 'Backend' (edit/admin/code view) start with WWW.mydomain... and in 'Frontend' (actual published view in browser) they start with CDN.mydomain...

So my question is, do I use the Backend or Frontend (www. or cdn.) for the URL in both image sitemaps and in 301 redirect final destination?

My current sitemap for example seems to be using www rather than cdn. : http://www.bosphorusyacht.com/sitemap-image.xml

Thanks for your help!

[RyanPurkey]

Right. Not everything is going to be served from cdn. It's most likely setup for your images so your sitemap will still reside on www. Make sure to point to the front end files though as those are the publicly accessible ones.

[emerald]

Hi Ryan,
Thanks for your answer - Sorry I didn't mean about the URL for the location of the sitemap - I think my question wasn't clear - may I rephrase it:

(1) Inside my image sitemap, the urls serve off the www. subdomain as bolded in the example below (not .cdn). I'm assuming this setup is correct as this was auto-generated by an Image Sitemap Generator - does the below image:loc look correct to you?

<url><loc>http://www.bosphorusyacht.com/yachts/</loc>
image:imageimage:lochttp://**WWW.**bosphorusyacht.com/wp-content/uploads/2010/09/istanbul-boat-rental.jpg</image:loc></image:image></url>

(2) For a 301 image redirect would I set it up like this:

Redirect 301 /wp-content/uploads/2010/09/istanbul-boat-rental.jpg
http://**WWW.**bosphorusyacht.com/wp-content/uploads/2010/09/istanbul-boat-rental.jpg

OR

Redirect 301 /wp-content/uploads/2010/09/istanbul-boat-rental.jpg
http://**CDN.**bosphorusyacht.com/wp-content/uploads/2010/09/istanbul-boat-rental.jpg

OR

How would I 301 this one?: username.net-dns.com/images/abc.jpg

Hope you can advise one last time - thank you!

[RyanPurkey]

Sorry I missed this follow-up earlier. Within the site map you'll want to change the http://WWW to http://CDN for these image files. The www version of your site, and the cdn server are on two different IPs / server. You want images to be serving from the CDN one.

For 2, if you do use 301 redirection I'd recommend scripting it so that the script inspects whether or not it's an image file and then applies the cdn change. A pro in your area that works with REgex and htaccess will be able to guide you through that.

The username.net-dns.com thing... That's not your server is it? You can't apply redirects on servers outside of your control.  Cheers!