Canonicalization is the process that search engines use to determine the best URL or website address when several different choices exist. This is a common issue that is predominantly related to home page files at the root level. For example, to a web user, the following URLs all appear to be the same:

www.yourdomain.com
yourdomain.com
www.yourdomain.com/index.shtml
yourdomain.com/default.asp

However, search engines view the above URLs as different pages. Web servers see each URL differently and treat each independently, therefore each of the above URLs could display different content if desired. When a search engine attempts to “canonicalize” a URL, it seeks to choose the best page to represent the website.

The simplest way to discover if you are experiencing this issue would be to perform a search using part of the content found on your homepage. If more than one result appears on the search engine result pages, you may want to correct the issue using a 301 redirect on your web server. The 301 redirect will instruct the search engine as to which URL you desire to be “canonical.” In addition, this 301 redirect will permanently readdress to the specified URL, as seen in the sample below:

When a user types this address into their browser:

www.yourdomain.com

The 301 redirect will redirect any request to the specified address:

www.yourdomain.com

I have seen countless websites displaying the same content on two or more different URLs. Search engines penalize websites that feature duplicate content, causing problems and poor performance for the site owners in obtaining organic rankings. Ironically, most website owners aren’t even aware of this problem and if they are, they don’t know it pertains to their sites

This article was written by David Montalvo, Senior SEO and Director of Business Development at UnReal Web Marketing