Google: splitting and merging websites can cause problems

In a webmaster hangout on YouTube, Google’s John Mueller talked about merging two websites into one. He also talked about splitting one website into two separate websites.

Google can handle simple domain changes

If your website moves from one domain to another, Google can handle that. To make sure that everything runs smoothly, redirect old page URLs to new page URLs with a 301 redirect and make sure that each old page has a counterpart on the new website. Do not redirect all old pages to the home page, but redirect all pages individually.

“Splitting and merging sites is always really tricky for us. Moving sites is generally a lot easier because we can pass all of the signals one to one.

It’s a lot easier for us to debug as well. If something goes wrong someone can look at it and say ‘this is the old state, this is the new state’ and we can compare that.”

Splitting a website into multiple sites is more difficult

Splitting a website into multiple sites is more complicated than a simple domain change. The new websites should have individual counterparts to the old pages from the previous website.

John Mueller also said that you cannot simply add the traffic of the previous website to calculate the traffic of the new websites:

“If you’re splitting or merging sites then there’s no really clear and well-defined ‘new’ and ‘old’ state. They’re not really mapped one-to-one there because you’re taking one site you are turning into five and it’s a completely different situation for each of those individual sites.

You can’t take those five sites and add them up and come up with a new [website] with the same number as before. That’s something that takes a lot longer to be processed. […]

We have to reprocess everything […] I don’t think we’d have any system to understand ‘this entity has moved from this domain to this one of these five domains’. I think it’s really something we have to figure that [out] almost on a per-page basis.”

Merging multiple websites into one also isn’t easy

John Mueller said that the same problems apply if you want to merge multiple websites into one:

“You have the same situation if you take multiple sites [and] merge them into one site. […] You can’t add them all up and that’s the traffic you get. […]

Make sure that you have something that matches the old content so that people who are explicitly looking for their own stuff they will have someplace to go.”

You can watch the full video here:

Optimize your pages now

From an SEO point of view, your web pages won’t benefit if you merge or split websites. Better optimize your existing pages so that they get better rankings. The tools in SEOprofiler help you to get higher rankings on Google and other search engines.

You can create your free SEOprofiler account here:

Create free account

Johannes Selbach

Johannes Selbach is the CEO of SEOprofiler. He blogs about search engine optimization and website marketing topics at "".