There are many people that will tell you to "remove the www" or it can cause duplicate content penalties. First just to point out, that is not true, Google does not penalize you for having www.example.com and example.com both have the same content. Yes it is counted as "duplicate content", but Google is smart, it knows you don't mean anything by it. Google will not penalize you for duplicate content based on www or non-www both working and showing the same duplicate content. Don't take our word for it, read This google article about duplicate content. Near the bottom it says this:

Duplicate content on a site is not grounds for action on that site unless it appears that the intent of the duplicate content is to be deceptive and manipulate search engine results. If your site suffers from duplicate content issues, and you don't follow the advice listed above, we do a good job of choosing a version of the content to show in our search results.

Now that it is clear, you are not penalized whether or not you force using www or not using www, it is still a very good practice to choose one or the other, then create a "301 redirect" from one to the other. In other words, while you may not be "penalized" for having duplicate content, it is still best to use a solution to take care of that duplicate content, so that Google and other search engines know the "preferred" URL to use.

Whether you use www or not use www is your own personal preference. There is only one "technical" reason for using one over the other, and it is a very minor reason: If you do not use www, that will result in requests to download images and things for the page, to have 3 less characters, and therefore be very slightly faster. In reality however, this "advantage" is probably not going to be noticeable either way.

On our own website http://geodesicsolutions.com we use without www, and that was a personal choice of the employee that was setting everything up at the time years ago. You will notice that we have the same re-direct mentioned in the No use www section, if you try going to www.geodesicsolutions.com it will re-direct you automatically to remove the www.

Below is an example of what you would add to your .htaccess file. What this will do, is when you go to example.com, it will re-direct you to www.example.com automatically. The example below works in such a way that it will not interfere with using sub-domains for regions.

Add the following lines below everything added that is already in the .htaccess file (or create a new file if it is not already on your website):

# Use www
RewriteEngine On
RewriteCond %{HTTP_HOST} ^example.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]

In the code, replace example.com with your own domain.

Note: if you already see the RewriteEngine On line further up in the .htaccess file, you can leave that line off.

Next, in your admin panel, make sure that all of the URL settings use www version of your domain name.

Below is an example of what you would add to your .htaccess file. What this will do, is when you go to www.example.com, it will re-direct you to example.com automatically. The example below works in such a way that it will not interfere with using sub-domains for regions.

Add the following lines below everything added that is already in the .htaccess file (or create a new file if it is not already on your website):

# Do NOT Use www
RewriteEngine On
RewriteCond %{HTTP_HOST} ^www.example.com$ [NC]
RewriteRule ^(.*)$ http://example.com/$1 [R=301,L]

In the code, replace example.com with your own domain.

Note: if you already see the RewriteEngine On line further up in the .htaccess file, you can leave that line off.

Next, in your admin panel, make sure that all of the URL settings do NOT use www version of your domain name.