It is Normal For Old URLs To Still be Visible in Search Results After Performing a Domain Migration
When performing a domain migration, it’s perfectly normal for pages from the old domain to still appear in the search results. However, it is likely the cached page is already seen as the new domain URL, as Google will identify that the old URL is an alternate version of the new one. John does not recommend using the URL removal tool for this as it won’t provide a long-term fix, it will just hide the URLs in search results.
Blocking Googlebot’s IP is The Best Way to Prevent Google From Crawling Your Site While Allowing Other Tools to Access It
If you want to block Googlebot from crawling a staging site, but want to allow other crawling tools access, John recommends whitelisting the IPs of the users and tools you need to view the site but disallowing Googlebot. This is because Google may crawl pages they find on a site, even if they have a noindex tag, or index pages without crawling them, even if they are blocked in robots.txt.
Adding New Language Versions Alongside Migration Can Delay Processing
For Google to be able to process site migrations quickly, they need to be one-to-one moves. Adding new language versions alongside a migration means Google will need to process each of these versions separately which will take longer.
Featured Snippets Can be Switched Quickly After Migration if Site Structure is Consistent
If Google is able to clearly see that a site has moved, all the associated signals and features such as featured snippets and knowledge panels will be moved across to the new domain as long as the site structure and internal linking remains consistent.
Make Sure Hosting & Redirects Are Set Up Correctly After Migration so Google Doesn’t Think Site is Offline
If part of your website doesn’t work when Google is trying to access it, such as www. pages, Google could assume that the site has gone offline. Ensure that redirects and the hosting is set up correctly to avoid this from happening.
Make Sure Old Site Isn’t Being Blocked from Crawling During Migration
During a site migration, if the old site is being blocked from being crawled by Google in robots.txt, this can cause issues with Google being able to process the migration and pass on signals to the new site.
Use Redirects Rather Than Orphaning an Old Page Before a Site Migration
When implementing a site migration, redirect old pages as soon as possible rather than removing internal links to them to try and encourage Google to drop them from the index.
Block Staging Sites From Being Crawled by Google
You should block Google from indexing your staging site as it can cause problems. You can block access based on Googlebot’s user agent, or using robots.txt.
Include Content That Matches Old Website Versions When Merging Sites
When merging multiple sites into one, John recommends including some content on the destination domain that matches the original domains that have been merged.