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.
HSTS Isn’t Used as a Ranking Signal
HSTS doesn’t play any part in rankings. The main consideration from Google’s perspective is that it shouldn’t be added to a site during a time of fluctuation, like a migration. Make sure you only add it once rankings have settled and a migration has been completed successfully.
A/B Testing During a Site Migration Can Delay Google Processing the Move
If you’re running large scale A/B testing during a site migration, this can confuse Google’s picture of your site and prevent it from running an algorithm to easily switch all of your URLs across to the new version.
Use a Crawling Tool to Assess & Compare a Site Before & After a Migration
Before launching a site migration, John recommends using a crawling tool to get a full picture of your site’s status and signals (such as internal linking, canonicals etc.) both before and after the migration to compare.