Google Webmaster Tools – Associate Multiple Website URLs to One

Google Webmaster Tools - Associating Multiple Domains

Recently I worked on a project with multiple URL’s all pointing to the exact same content.  This was killing this particular sites SEO rankings as the content was split amongst multiple domains.  In the Google Webmaster tools there were about 10 different sites all registered and all competing against each other.

Google Webmaster tools only allows webmasters to associate the www subdomain together with a subdomain-less domain.  Meaning, only “” and “” can be associated together.  This also means the “” and “” cannot be associated together.  

The most troublesome of these is that “” and “” cannot be associated together.  There are many reasons why these different domains cannot be associated together when it comes to SEO.  For this post we do not want to get into them.  Rather we want to emphasize that Google treats all of these domains as unique.  

As a result of Google treating these as individual sites we need to ensure that we do not have duplicate content.  This might mean that a migration of some sort has to occur.  When a migration is needed that are a few basic steps to remember:

  • Physically migrate the content from one location to another.
  • Setup the properties in Google Webmaster tools.
  • Setup a 301 Redirect (using htaccess rules for example) from your old content to new content.
  • Perform a migration of Google rank data using the change of address tool.

You can use the Google Change of Address tool to help in moving your existing page ranks and data over.  This tool only works when you move an entire site from one domain to another.  Meaning – it does not work for moving contents from one folder to another.

Let’s look at a few scenarios where you might have multiple urls setup that may require a migration.

Different protocols such as Http and Https

The most common situation is probably the case of handling both http and https.  Remember though that these are two different sites to browsers, google and website visitors.  The exact same code might be serving the content – but they are two different sites.

Since these are two different sites we will want to avoid serving the content under both HTTP and HTTPS versions.  In this case it is probably smarter to go all in and serve our content under HTTPS unless there is a strong reason not to.  If we find that we need both an HTTPS and an HTTP version, you will want to set these up as two different sites so that they do not compete with each other.  An example could be an HTTP version that focuses on the marketing aspect of your product and then an HTTPS version that handles the checkout and account routines.

If you have content under HTTP that now needs to be under HTTPS you will want to perform a full migration. This may mean moving content or it may not.  You will need to setup new properties within Google Webmaster.  We will also want to enforce the usage of HTTPS on our site.  This generally requires us to register some sort of .htaccess ruleset.  

Note: If you are using a software program such as WordPress, you can easily change your sites URL in the settings console.  however this causes a user to be forwarded to the new destination when they land on your HTTP version of your site.  This does not actually instruct search engines that old references and links to the HTTP version should be updated.  A 301 redirect rule is needed for that.  Before doing any rewrite rules, be sure to proper test your content under the new URL.  Here is an example of what a 301 redirect rule might look like for an example site.

RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$$1 [R=301,L]

This particular post isn’t focusing on the exact rewrite rules needed – so be sure to test and adjust the proper rewrite rules as needed.

At this point you have effectively migrated your site from HTTP to HTTPS.  

Different Top Level Domains such as .com and .org

Another common example is when you have a .com and .org version (or similar TLD) of your domain name.  

The same rules apply in this situation as they did with our HTTP versus HTTPS example. and are two different sites and should be treated as such.  If you decided to snatch up all of the different top level domains of your domain name, you will need to setup some sort of redirect for them to your principal domain.

Remember that different Top Level Domains were created to help classify and distinguish differences between large websites.  For example, a large corporation might house their principle product offerings and business services off of their “” website.  However the same business might also house a website that showcases their volunteer work and community involvement through their “” website.  This example also applies for large companies that provide a unique client experience under different country based TLD’s such as .au or .ca, etc. 

The key thing to remember with all of these examples, is that each of these TLD based sites are unique sites.  Google treats them as unique and so should you.  Be diligent in making sure that you do not have content competing with each other and diluting the strength of your brand.  Choose one to be the principle as appropriate and then redirect the others as needed.

Different Sub Domains such as and

Different sub domains is probably the next most common example of this situation.  Just like the other two examples, the same rules end up applying.  Each sub domain is treated as an individual site.

Remember Sub domains were created to allow webmasters flexibility in being able to create multiple websites from just one subdomain.  A good use of this example would be a college that has their principal information off of their “” website.  This same college also allows their Photography club to host their own website off of the college domain under the subdomain of “”


The main conclusion from this post is that whether you are running multiple sites due to Protocol differences, Top Level Domain differences or Sub Domain differences, each of these sites are unique and cannot be merged together.  As the webmaster you should setup your content to be associated with only 1 domain.  Use redirects as appropriate to move content from a secondary domain to your primary domain.  Be sure to also take advantage of the Google change of address tool when you are done moving your content.

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