In a Question and Answer segment during one of his hangouts, John Mueller was asked about external links during a site migration.
One SEO professional explained to John that they are relaunching a customer website and moving it from domain A to domain B, and they are reconfiguring redirects that point to domain A for domain B.
Their question at this point is: will page authority and page ranking be negatively affected if there are many backlinks to domain A? Will future backlinks, which point to domain A, also be affected?
Will the domain authority from the old domain automatically be inherited by the new domain, even if there are a lot of links?
John explained that there are two aspects here. On one hand, if you’re moving from one website to another, and you use the redirects to move things over using various tools (such as the change of address tool in Search Console), then this helps us to really understand that everything from the old domain should just be forwarded to the new one.
That’s a situation where, as much as possible, Google will take everything from the old domain and just apply this to the new one.
The other aspect is that Google does look at things like canonicalization on a per page basis. For canonicalization, they examine many factors that come in. For example, the following may all play a role:
- Redirects
- Internal linking
- Rel=canonical on the pages
- External links
What could potentially happen in more edge cases is that, if Google sees many external links going to the old URL, and maybe even some internal links going to the old URL, Google may actually index the old URL instead of the new one.
Because from Google’s point of view, it begins to look like the old URL is the right one to show and the new one is maybe more of a temporary thing.
Because of this, John recommends that when you do a site migration from one domain to another, is not only to setup the redirect, and not only use the change of address tool, but also go and try to find the larger websites that were linking to your previous domain and see if they can update those links to your new domain.
Basically, just make sure that everything you do is aligned with ensuring that Google can focus on the new domain rather than on the old one.
This happens at approximately the 42:03 mark in the video.
John Mueller Hangout Transcript
John (Submitted Question) 42:03
We’re relaunching a customer website and moving it from domain A to domain B. We are reconfiguring redirects from domain A to domain B. The question now is whether the page authority and page ranking will be negatively affected if there are many backlinks to domain A.
And also future backlinks, which will point back to domain A. Is the domain authority from the old domain automatically inherited by the new domain, even if there are lots of links?
John (Answer) 42:42
So I think there are two aspects here. On the one hand, if you’re moving from one website to another, and you use the redirects, kind of to move things over and use the various tools that we have, like the, or the change of address tool in Search Console, then that helps us to really understand everything from the old domain should just be forwarded to the new one.
So that’s kind of, essentially a situation where, as much as possible, we’ll take everything from the old domain and just apply it to the new one. The other aspect there is on a per page basis, we also try to look at canonicalization.
And for canonicalization, we look at a number of different factors that come in. On the one hand, redirects play a role, things like internal linking play a role, the rel canonical on the pages play a role. But external links also play a role.
So what could happen in kind of probably more edge cases, I guess, is that if we see a lot of external links going to the old URL, and maybe even some internal links going to the old URL, that we actually index the old URL instead of the new one, because from our point of view, it starts to look like, well, actually, the old URL is the right one to show and the new one is maybe more of a temporary thing.
And because of this, what we recommend, when you do a migration from one domain to another, is not only set up the redirect, and not only use it the change of address tool, but also go off and try to find the larger websites that were linking to your previous domain and see if they can update those links to your new domain.
Kind of just making sure that everything that you do is aligned with making sure that we can focus on the new domain rather than on the old–than on the old one.