I am moving a site off of a CDN where all the images are cached and served:
https://some-cdn.example/my-image.jpg
The image will now live here:
https://myurl.example/my-image.jpg
Many of these images are #1 in Google image search for our search terms. Since the CDN URL doesn't point to any domain I control I can't add 301 redirects. Is there anything that can be done?
If the URLs aren't on your own domain and the CDN doesn't have any facility to introduce redirects, then there is nothing you can do.
It probably won't matter all that much for SEO. In the case of images, they are likely only used on your site. There are usually very few external uses of or links to images. So when you use the new image URLs on your site, Google image search will pick up on the new images within a few months.
Next time you use a CDN, it is advisable to assign a subdomain from your own domain name to that content. That way when you terminate the CDN, you still have control over the URLs.
Ensure you update internal links, update or add a XML sitemap, ensure alt attributes are carried over. CDNs are a great way to deliver your content to users faster and is often recommended by Google as a page speed component.
Ensure your sub domain is allowed to be crawled from the robots.txt file.
It’s unfortunate that you can’t setup redirects though Google should see what you’ve done.
