Recently, when Wordpress 2.9 was released I saw it was supporting something called rel = “canonical”. I wondered what it was and googled for it and found this element was pretty much useful and interesting. So, I thought I would share this piece of information on my blog.
You might have seen many URLs pointing to the same/similar page many times. For example,
- www.example.com
- example.com
- www.example.com/index.html
- example.com/home.aspx
These type of URLs may cause search engines to look at your content as duplicate and thus your search engine rankings may go down. In such cases, using canonical elements can reduce the problem.
So, What’s the deal with rel =”canonical”?
When many URLs point to the same or more exactly, similar page then that results in duplicate content. Bloggers, SEOs and website owners avoid this by using 301 redirects, which redirect the search engines to the new URL. This rel=”canonical” element has a similar functionality. While 301 redirection works across different domains, rel=”canonical” works only within a domain. However, canonical elements even work for sub-domains too.
How To Use The Canonical Element?
Using the canonical element is very simple. All you need to do is put a piece of tag/element at the top of your non-canonical page. For example, consider two URLs like “http://www.example.com” and “http://www.test.example.com”. Now, if both the URLs lead to the same page, search engines consider it as duplicate content. To avoid this, you can add the canonical element at the top of the non-canonical page (http://www.example.com).
<link rel="canonical" href="http://www.test.example.com/>
Note: This should be added to the head section of the page. (i.e., after <head> tag.)
Imporant:
If you add the canonical tag to both the pages, this creates an infinite loop. In such cases, search engines have the rights to decide which is better.
Canonical elements do not direct the search engines to a different page, but instead just gives a suggestion to go to that page. To be short, canonical tags are not directive, they are just suggestions. If you have two URLs say, http://www.example.com and http://www.cartoon.example.com which are completely different and you try to add canonical element between them, search engines may not consider it. So, you can add canonical tags only to same or similar pages.
So, this canonical element can be of great help to bloggers who blog from blogger platform. Blogger users often suffer from duplicate content issues. Using canonical tags can reduce this. For more information about this, you can watch the video by Matt Cutts, Google engineer below.
I’m trying to resolve duplicate content issues with my Blogger blog, as indicated by my Webmaster Tools. Still trying to sort out where & how to implement the rel “canonical” element. In the Cutts video above, he doesn’t refer to how this applies to Blogger. So unless there’s some broader understanding I’ve missed here, I’m still lost…