Help with managing rel=canonical efficiently

[shaunm]

Hi All,

Is adding canonical to the canonical page itself is same like adding canonical to the duplicate pages?

Say the unique page exist at
example.com

and the duplicate variants are at
example.com/?itemid=2012&view=default
example.com/?itemid=2012

Instead of adding canonical to these duplicates pages, can I just add the canonical to the actual canonical page which is example.com, by making it its own canonical? Will that work?

I'm asking this because we are using a forum software that creates so many URLs for a single URL through various parameters in an endless loop. It's really hard to find out those URLs since because they depend on what page you are in.

So I was just wondering why not add the canonical to the canonical page itself instead of adding the canonical to the uncountable number of duplicate pages that Google might be able to find.

Is that possible? Has anyone experimented this before? Is that worth the experiment?

By they way I'm trying both rel=canonical and webmaster tool parameter handling to make sure I'm through.


Thanks!

[phranque]

is this "april fools"? =8)

the canonical url is precisely where the link rel canonical is unnecessary and actually useless.
the purpose of the link rel canonical is to specify the canonical url for content served from non-canonical urls.


i think you are assuming a url without the query string is the canonical url and that is not always the case, nor are query strings themselves necessarily noncanonical.

[shaunm]

Thanks @phranque

is this "april fools"? =8)

Not necessarily :-)

the purpose of the link rel canonical is to specify the canonical url for content served from non-canonical urls.

Actually we are adding canonical to all the pages in our website, both canonical and non-canonical pages. We are making each canonical page as its own canonical only for a single reason.

The content is often getting scraped including the template/nav everything. And when the scraped content is hosted somewhere elese by the scraper he woun't be necessarily looking into the html codes and remove the canonical tag.

Even if he's removing the canonical and adding a canonical pointing to his website, I strongly believe that Google uses the history of the canonical content like when it was published first and where it was published first. So adding one line of code will not have any negative impact but only positive signals to Google saying that we are unique (among all other ways)

As for my op, I asked this somewhat weird question because Google says

When Google detects duplicate content, such as variations caused by URL parameters, we group the duplicate URLs into one cluster and select what we think is the "best" URL to represent the cluster in search results. We then consolidate properties of the URLs in the cluster, such as link popularity, to the representative URL. Consolidating properties from duplicates into one representative URL often provides users with more accurate search results.

So I was just thinking if adding canonical to the canonical page itself will signal them that 'hey this is the best page among the cluster pages you have collected'

Does that make any sense at all lol?

i think you are assuming a url without the query string is the canonical url and that is not always the case, nor are query strings themselves necessarily noncanonical.

Yeah. But what if it's the case for some set of pages that you know for certain? :-)


Thanks,

[Planet13]

This is the part that concerns me:

"I'm asking this because we are using a forum software that creates so many URLs for a single URL through various parameters in an endless loop."

Is there no way to modify the forum software so that it DOESN'T do this? That is what I would focus on first, if at all possible.

If not, one thing is that you can use parameter exclusion in webmaster tools to help with this as well.

And yes, I would have the canonical tag on the "original" page as well as any variants.

[aakk9999]

It is true that canonical on the canonical page is useless, but more importantly (at least for Google), it does no harm.

Will setting the rel="canonical" attribute of a page to itself cause a loop
Matt Cutts, 25 May 2011
https://www.youtube.com/watch?v=U8eQgx-njk4 [youtube.com]

I have seen many CMS implementations where a canonical is entered together with the other page details (e.g. fill in your page content, fill in your page title, fill in meta description, fill in your meta robots, fill in your page canonical).

The script then outputs this canonical whenever this page content is displayed. This would result in the canonical being the same as URL for the canonical page, but stops additional coding logic in only outputting canonical if the request URL is not equal to the canonical URL.

The content is often getting scraped including the template/nav everything. And when the scraped content is hosted somewhere elese by the scraper he woun't be necessarily looking into the html codes and remove the canonical tag.

Yes, this is a good reason to have a canonical pointing to itself since Google supports cross-domain cannonicals.