WWW vs. non-WWW - Do you know what side you're on?
Most people don’t give much thought to the “www” they see in many web site URL’s. The fact of the matter is “www” is not needed and can be dropped if desired. That portion of a domain, prior to the main domain name is called a sub-domain. You probably have seen URL’s set up with words prior to the domain such as red.domain.com which is a perfectly acceptable technique. So how you set up your URL’s is not a big concern; BUT making them uniform is very big!
What all webmasters should do is decide which version they wish to go with; either the “www” or the “non-www”, such as http://domain.com/ or http://www.domain.com/.
The essential concept to think about is;
http://domain.com/ and http://www.domain.com/ are in fact two separate pages. And if they are both indexed, you have two separate pages, with exactly the same content; a search engine taboo if ever there was one.
The reason you need to decide, and then make them uniform is eventually both versions will become indexed by search engines, and those search engines will have great difficulty deciding which one to favor. If they cannot figure this out you end up with what they call Canonical pages. There are many problems with this phenomenon, but the two worst are the splitting of page rank, and the search engine tagging you with a duplicate content penalty because there are basically two identical copies of your content floating around.
If you go to your site, try getting to it with http://domain.com/ and see what happens. If it comes up just like that, note the Page Rank that Google assigns to it. Then go to the site with http://www.domain.com/ and note the Page Rank assigned to that form. Try this with interior pages as well. Often you will see a difference in the two, one being lower than the other.
How does this happen? Well pages get indexed in search engines by people linking to them. That’s essentially the only way a page gets indexed, is someone, somewhere (including pages your own site) is linking to it. So if someone links to your site as http://domain.com/ that’s the URL the search engine will recognize cache and index.
So what should we do to avoid this? The first step is to decide the version you want. Once you have decided, you want to “permanently redirect” the version you don’t want to the version you do want. This is done through your server. There are different types of servers that require different commands. But as an example of what this might look like, if you had an apache server you might employ this;
Create a file called .htaccess (you need the . infront of it) and add
the following 4 lines of text to it:
Options +FollowSymLinks
RewriteEngine on
RewriteCond %{HTTP_HOST} ^yoursite.com [NC]
RewriteRule ^(.*)$ http://www.yoursite.com/$1 [L,R=301]
Replacing yoursite.com with the domain you wish to redirect. Now upload this file to the main web root of that domain.
The above concept, done through your server is the most controllable method to accomplish this. For anyone using the Google Webmaster Tool, there is actually a section in there that allows you to tell Google which version you want!
So, the next time you see a site that comes up as http://domain.com/ you might wonder if its by accident or design.
