If your site is hosted on a Linux/Apache platform, you should have access to an Apache module called Mod_Rewrite. This utility is a very robust URL rewriting/redirecting tool controlled using .htaccess files placed in various folders on your web site. You should be able to simpy modify the .htaccess file in the root of your web to include the following RewriteRule…

NOTE: In all of the following code examples, you will have to remove the space after the opening ‘< ' for both the opening and closing IfModule tags.

If you prefer the non-www version of your URLs then you would want something like this:

< IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^www.example.com$ [NC]
RewriteRule (.*) http://example.com/$1 [R=301,L]
< /IfModule>

If you prefer the www version of your URLs then you would want something like this:


< IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^example.com$ [NC]
RewriteRule (.*) http://www.example.com/$1 [R=301,L]
< /IfModule>

This will work on pretty much any Linux/Apache server configuration regardless of the technology platform your site is built upon.

I typically put this code AFTER any specific URL redirects I might have in my .htaccess. Typically specific redirect rules should appear first in the .htacces, and general rules like these should appear at the end.

If you’re running WordPress, you’ll want to put the above code just before the WordPress section. For example, on a WordPress site that prefers www you might end up with:


< IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^example.com$ [NC]
RewriteRule (.*) http://www.example.com/$1 [R=301,L]
< /IfModule>

# BEGIN WordPress
< IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
< /IfModule>

# END WordPress

You may be tempted to place the RewriteCond/RewriteRule for the URL canonicalization inside the WordPress block, but don’t. The next time you upgrade WordPress, the upgrade process will overwrite everything inside that block and you’ll use your URL canonicalization redirect.

If you’re running WordPress, you will also need to log in and go to the Settings -> General admin screen. Once there, make sure the values in the WordPress Address (URL) and Site Address (URL) reflect the choice you have made.

Google’s Webmaster Tools also offers a way for you to specify your preferred domain (www or non-www). Again, if you use this tool to indicate to Google which version of your domain you prefer, MAKE SURE that it is consistent with the other settings in your .htaccess and within the WordPress admin’s general settings screen (if applicable).

It should be noted that Google’s Webmaster Tools preferred domain setting will ONLY fix this for Google. Implementing 301 redirects to specify a preferred domain works for ALL search engines.

You could even say media has somewhat programmed us to expect it. Even today when we type in a web address without the www we expect to see the www appended to the URL.

But it all comes down to choosing one or the other and sticking to it. If you choose one over the other it is always a good idea to 301 redirect. Just for the simple fact you can not control how other sites link to you. They may choose to use the opposite of what you have chosen. Just helps to reduce the chance of duplicate content and beats a split page rank/link juice issues.

Thumbs up on this very informative post.

If you’re not 100% sure of whether a 301 redirect is actually occuring, there are many tools on the web that will show you the browser/web server interaction including the status codes being returned. You can use the Firebug plugin for Firefox… or you can simply enter a www URL into this web page based http header tool and it will show you the interaction between the browser/crawler and your web server.