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Google’s Mueller on How to Successfully Implement Major Site Changes

Google's John Mueller offers advice on how to make major changes on a website without negatively impacting search rankings.

Image of a cat sitting on a laptop, obscuring the image Google's John Mueller that is peering from the laptop screen

In a Reddit discussion, Google’s John Mueller advised offered best practices for changing domains or redesigning and updating a site. He focused on both the positive and negative issues to be concerned about.

Mueller started by comparing changing domains to a redesign. He a domain change with no difference in site or content is not as disruptive as a redesign can be.

Domain Name Changes are Generally Safe

A one to one exchange is where the site structure and content remains exactly the same and only the domain name changes is a relatively safe.

Of course, there are other things that can go wrong, like a legacy spam penalty that is latent in the new domain.

But Mueller was speaking in general and making a relative comparison between two kinds of changes (domain change versus a redesign and update).

Mueller said:

“You’ll potentially see more fluctuations from the redesign / revamp than from the domain name change. Moving things 1:1 from one domain to another is – for the most part – a non-issue.”

Potential Impact of Redesigns and Site Structure Changes

Publishers generally make major changes to the design and site structure in order to effect an impact in site performance. Bright people don’t fix what isn’t broken, right?

Yet even though one endeavors to improve a site, there may still be unintended consequences.

Related: How to Avoid SEO Disaster During a Website Redesign

Mueller Says Watch Out For This

He describes the potential for upsides (better SEO) and downsides (negative impact on search rankings).

“Moving between CMSs, rebuilding a site, restructuring it: changing URLs, significantly changing the design, changing the internal linking, all of those things can significantly impact a site’s performance in search (and it can go up too, it’s not always down — you can do things to improve SEO after all).”

Stagger Your Changes

Mueller now advises that it may be useful to stagger your changes, to implement them in stages (phase 1, phase 2, etc.).

He mentioned staggering changes in the context of changing a domain and redesigning/updating the site structure.

The reason to stagger major changes is to be able to give proper attribution to improvements and to be able to understand what caused a negative impact as well.

Making changes all at once can make it near impossible to untangle which change negatively impacted rankings. Not implementing changes in multiple phases makes it considerably difficult to identify which change needs to be rolled back or improved.


“If you do that and move domains, you won’t know why there are changes, and that’s where a lot of the site move stories come from.

If you need to do both, I’d try to split it time-wise so that you can recognize any negative effects in each part, and take action to improve them.

If you do everything at once, you’ll never know what to fix, and even if things end up “same as before”, you won’t know if one part went down, and was compensated by an improvement on the other part. Keep things controllable & trackable.”

When Major Changes Happen Beyond Your Control

Mueller then commented on the situation where changes are happening and you are powerless to effect a major influence.

I’ve been in that situation as search marketing consultant. A large multinational corporation I was consulting for was purchased by a larger company in a multi-million dollar deal.

The original domain name was replaced by that of the larger company. The two websites were joined together.

When the domain change and site update happened (at the same time), I re-crawled the site to identify 404s. I then created a spreadsheet recommending to which pages they should redirect to and which pages should remain as 404. Other issues were identifying soft 404s, missing images and so on.

This is what Mueller said:

“Sometimes you can’t split things out, if you need to revamp & move for reasons above your pay-grade, try to keep things as controlled as possible (track all the details), and set expectations appropriately.

You can’t remove all risks, but knowing them makes it easier to make decisions, and to determine actions to take when they happen (which might be “hire more SEOs” instead of “fire all the SEOs”).”

Related: Google Explains How to Successfully Migrate Sites


Changing domains can be painless if there are no changes to the site structure or a major redesign.

Redesigning a website and/or updating the site structure is a path to improvement but could introduce unintended consequences.

When effecting multiple changes, try to stagger the changes in multiple phases in order to be able to roll back a bad change and fix it.

Not staggering changes can make it difficult to pinpoint what went wrong (as well as what went right).


How to safely transfer sites without losing domain authority?


Can domain name changes negatively impact SEO?

Most likely no. Google says moving things 1:1 from one domain to another is – for the most part – a non-issue.

Can a website redesign impact SEO ?

Yes. Google confirms that rebuilding a site or changing its design can significantly impact a site’s performance in search. Changes like this can have upsides (better SEO) and downsides (negative impact on search rankings).

Can website restructuring impact SEO?

Yes. Google confirms that changing URLs or internal linking can significantly impact a site’s performance in search. It can either improve or decline.

Category News SEO
SEJ STAFF Roger Montti Owner - at

I have 25 years hands-on experience in SEO and have kept on  top of the evolution of search every step ...

Google’s Mueller on How to Successfully Implement Major Site Changes

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