Canonical Tag on All Pages

[smulto]

This is a new one for me.  I have a client that has a canonical tag on almost every page of their site.  Even on pages that don't need it.

For example on http://www.client.com/examplex

they had code:

Maybe I have missed something, but is there a reason for this?  Does this hurt the ranking of the page?

[LesleyPaone]

Why would you think a page would not need one? It is hard to tell from the example you gave what you meant, but I take the stance that every page needs one.

[smulto]

Even when it references the page that it is on?  That is where I am a little baffled.  It is like saying this page you are looking at is the same as the page you are looking at... right?  (page x is referencing page x)

Again, might be out of the loop here, so want to verify.

[LesleyPaone]

Oh ok, I see what you mean. What it is actually saying is "this page you are looking at is the one true source". It basically makes a correlation with the search engines between the content on the page and what page that content should be on, in a lesser sense if it is found on another page.

[William.Lau]

There isn't a major negative effect when using canonicals even when they are not needed. Some CMS use sitewide canonicals to easier tackle duplicate URLs. So if a base URL is using parameters, the CMS might have been setup to follow back to the canonical URL.

A quick example would be: view-source:http://www.expedia.com/

[QAD_ERP]

I noticed you have:

_For example on http://www.client.com/examplex_

they had code:

The URL in the canonical code has a trailing slash at the end. Is that a mistype, or Is the site using canonicals as a way of addressing duplicate content by pointing the trailing slash version to the non trailing slash version?

If the CMS automatically creates two versions of each page with and without the slash, that might be one reason to have canonicals on every page.

[smulto]

It looks like it was a typo on my end.    Thanks ...  great catch.