LeadQual Blog

Google just announced a new feature that allows you to specify the canonical URL for a page.  Yahoo also supports this tag, and MSN intends to as well.

Many websites can show the same content under different URLs.  Often this is just how many ecommerce and content management systems work — they generate URLs with various tags, parameters, path names, etc as a way to allow the back end technology to keep track of the page being displayed, as well as the context in which the page was generated (e.g., the catalog category for an ecommerce site, where the product being displayed may be shown in several categories).

For example, the following all might be the same page:

• www.mysite.com/icecream/vanilla.html
• www.mysite.com/desserts/vanilla-icecream.html
• www.mysite.com/products.php?type=vanilla&category=icecream
• www.mysite.com/products.php?type=vanilla&category=desserts

You can also get variations based on inconsistent capitalization:

• www.mysite.com/IceCream/Vanilla.html
• www.mysite.com/icecream/vanilla.html

The problem with showing the same content under different URLs is that it can damage your SEO rankings.  This is because search engines have algorithms to detect and filter duplicate content (thus your page may not be put into the index, or be delayed in appearing).  In addition, if your inbound links point to various instances of URLs for the same page, your page rank is diffused and the page will not rank as high.

The new tag allows you to specify the canonical (that is, “real”) URL for each page, regardless of the URL currently used to display it.  You do this via a <link> tag, as follows:

<link rel=”canonical” href=”http://www.mysite.com/icecream/vanilla.html” />

The above tag could be put on all of the above variations, and Google will focus all page rank and indexing to that canonical URL.

If you have issues with canonical URLs on your website, and you cannot easily resolve them, it is a very good idea to use this feature.  Ultimately, it would be better to just have consistent use of canonical URLs on your site if that is possible so you don’t have to use them, but this is a great alternative otherwise.

If you run your site on a Windows server, and have problems keeping capitalization of URLs consistent, I would recommend using this.  Again, better to have good standards and stick to them, but this can be a good catchall.

Let’s hope MSN follows suit on this one quickly.  It is a good idea.

For more information on this, see  http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html

John Erickson
LeadQual

Tags: google, Search Engine Optimization, SEO, yahoo

This entry was posted on Friday, February 13th, 2009 at 12:09 am and is filed under Search Engine Optimization. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.