Feb 2009


The 3 major search engines agree on a way to tackle duplicate posts within your site.   It has been a problem before when a certain web page can be accessible via different URLs.

Example is


In some websites, the same web page can be accessed by

  • www.example.com/products?trackingid=7828
  • www.example.com/products?orderid=23424
  • www.example.com/products?printable=yes&trackingid=234&ordernum=2432

In essense, all these 3 pages are in reality referring to the same web page but is only passing different paramters to the web page server side script.

The problem before is that the search engines treat all these  URLs as different and therefore all pagerank, link juice, and scattered among these urls and some might even argue that duplicate penalty might be imposed by the SEs.

Now, the 3 big search engines agree on a way to fix this.  It is call the “canonical” tag.  What you do to fix is to include a similar tag like thisin between your HTML’s head tag.

<link rel=”canonical” href=”http://www.example.com/products” />

The above tag indicates to the crawler that the URL it is present on should be represented canonically as http://www.example.com/products. This would eliminate the following duplicates:




So check you websites and apply this stuff go the maximum SEO benefit.

Want to see a real live example? Check this post via these 2 urls.


Then check the HTML source of both pages and see the “canonical” element in the link tag somewhere in between the tags.

I used a wordpress plugin to implement this “canonical” solution.  There is a more direct approach which is to insert a small php code at the template (usually header.php) as discussed by Dexter.

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