Webmasters Skeptical But Loving New Canonical Search Engine Tag

Feb 13, 2009 • 9:25 am | comments (10) by twitter Google+ | Filed Under SEO - Search Engine Optimization
 

Yesterday, Google, Yahoo and Microsoft announced together a new way to handle internal duplicate content issues with a new "canonical" header tag. Vanessa Fox does an excellent job explaining what it is all about in her piece at Search Engine Land.

So for all duplicate pages, you insert this tag in the header elements of those pages, specifying the main URL. The tag looks like this:

<link rel="canonical" href="http://www.example.com/true-url.html" />

Google, Yahoo and Microsoft have detailed explanations of how they work.

Three main things:

(1) This works only internally, not across domains. (2) Treat this like you would a 301 redirect, so be careful (3) Search engines consider this a "hint" and do not have to abide by it (just yet)

Outside of that, there is good recaps on this at Techmeme.

We have a ton of Q&A on this from our live coverage of the Ask the Search Engines panel from SMX West. I am sure your questions are answered in that panel or in the discussions below.

This tag can be confusing, because it is new. But after webmasters begin to understand where, if and how to use it, they are more likely to love it.

JohnMu said in a forum post:

Here are some examples where this could be used: - Web-shops (mutliple URLs depending on how you got to a page) - Sites that work with Session-IDs within the URL - Ad-tracking URLs (eg using AdWords + Analytics) - Affiliate tracking URLs - News sites with multiple URLs per article - Forums with multiple URLs per thread/page (eg "&highlight=", etc)

Plus, Yoast already posted plugins to support this for Wordpress, Magento and Drupal.

Forum discussion Google Webmaster Help, Cre8asite Forums, WebmasterWorld and Sphinn.

Previous story: Daily Search Forum Recap: February 12, 2009
 

Comments:

Barrie Adams

02/13/2009 04:06 pm

Very useful for the larger websites I manage, always suffering dupe content issues due to search and archive parameters, this should really help, can't wait to see it tried and tested to see its effect.

Macon

02/13/2009 04:13 pm

That's all well and good but it does nothing for the amount of simply unusable and unreliable content that is out there. I am still curious to see how someone can find a middle ground between human powered and mathematical search to provide some sort of filtering based on knowledge and experience. The only reliable start I have seen so far has been sweetsearch.com

Matt Cutts

02/13/2009 06:55 pm

Barrie Adams, the only thing I'd add is to take it slow at first (e.g. try it on just one site, or part of a site) to make sure you fully understand the tag and if it works for you the way you want it to. But I'm pretty excited. :)

Dietmar

02/16/2009 09:52 am

The time will prove it, anyone knows if a html-document is still valid with this tag?

JohnMu

02/16/2009 02:55 pm

Hi Dietmar, yes, documents will remain valid with this additional link element (provided you use the appropriate XHTML/HTML version). Search engines will generally not care which version (XHTML/HTML) you use so it's fine if you accidentally use the other version on your pages.

Barrie Adams

02/18/2009 03:16 pm

@ Matt Cutts - thanks, I am waiting for someone else to do the testing! I will implement fully once I have feedback RE its effect, though I'm tempted to try it out on a drupal site, Joost de Valk has released a plugin for it.

Ramu

07/29/2010 09:21 am

i am new to implement this type of tagging. i have on dount where we cah add this rel=canonical in the site. for example i have home page in this page i am showing my products. in the source page of my home page so many duplicate product page urls are there. in this senorio inside the link tag i have to provide home page link or product page link or i can add two links that contains both home and product page urls. Please help me i am strucking here with this doubt

Ramu

07/29/2010 09:23 am

i am new to implement this type of tagging. i have on dount where we cah add this rel=canonical in the site. for example i have home page in this page i am showing my products. in the source page of my home page so many duplicate product page urls are there. in this senorio inside the link tag i have to provide home page link or product page link or i can add two links that contains both home and product page urls. Please help me i am strucking here with this doubt

Chris

12/29/2010 05:15 pm

Canonical command is very effective and this works quite effectively.

fateunveiled

05/09/2011 06:39 pm

How would this be integrated into say a Joomla site where there is a standard .php template that generates all the code on a specific page? The CMS design uses the same template to generate the entire site? anyone have a clue of how this new tag will work on this platform? I have noticed that Joomla creates duplicates even with the greatest care to not to let this happen

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