Kristi Barrow

What is “canonical”?

In February, Google, Yahoo and Microsoft announced a new tag, “canonical” to help with duplicate content issues.

The idea behind the canonical tag is to direct the search engine to a preferred version of your URL. The canonical tag is different to a 301 direct as it gives the search engine a hint (not a directive as Google has publicly stated) as opposed to a 301 permanent redirect.  There seems to be good reasons to implement these on your sites which use:

• marketing tracks tags
• category and navigation parameters
• session ids
• any other parameter appended to the end of the URL

Is anyone using “canonical”?

The rel=”canonical” has been out for almost two months now, and I was interested to see if anyone had implemented it across their site.  I decided to look at Online Travel Agencies (OLTAs) in Australia to see if anyone had implemented the code:

Interestingly the only company who has implemented the code so far, Booking.com, is the one known for their SEM and SEO work.

Does it work?

Well the jury is out, and really it is too early to tell. The canonical tag is likely to help clean-up some messy sites, but there is not evidence so far that this has improved anyone’s rankings. However, in 3- 6 months it will be very interesting to see if this has had a material affect on SEO traffic for the companies that have implemented the tag. ( If anyone does have any positive stories from using “canonical”, please let me know.)

There is an excellent post from SEOmz about the Canonical tag, which is well worth the read – Canonical URL Tag – The Most Important Advancement in SEO Practices Since Sitemaps