Canonical to the page itself?

[seomasterbrasil]

Hello,

I'd like to know what happens when you use canonical to the same page itself, like:

Page "example.com"

rel canonical="example.com"

Does that impact in something? Bad or good?

See ya!

[Dr-Pete]

We're re-evaluating the canonical notice, as it's confusing to a lot of people. Our intent wasn't necessarily to say that the tag is wrong, but more of a "heads up" (in case there are potential problems). Unfortunately, there's no good way to automatically detect what page a canonical should point to, so we tend to have to use general warnings.

[seomozkey]

According to this video http://www.youtube.com/watch?v=U8eQgx-njk4 Matt says there is no penalization of any kind with a canonical tag referencing to the page itself.

However, I have noticed that SEOMoz doesn't like it. It keeps reporting thousands of canonicals in the "Notices" report as if there was something I should do about it.

watch?v=U8eQgx-njk4

[Dr-Pete]

Keep in mind that a lot of my organic SEO client work is helping people deal with massive-scale duplicate content problems (including Panda issues), so I'm probably a bit more hyper-sensitive than your average person

[Dr-Pete]

For some people, a "landing page" could have URL variants, like tracking parameters for affiliates. So, it's hard to talk about them in a vacuum. If you're talking about a regular main-nav page like "About Us", you'd almost never need a canonical tag.

[seomasterbrasil]

For e-commerce I think is very important, even more for the big ones, that have a lot of filters of princing or color that are in fact other URLs. There we need to input a canonical.

But for landing pages, N1 deep, that seems like a hotsite, when the company just sells one online service, I can't imagine what kind of benefits using "self canonical" in a page like this.

Sorry for making this longer, I should've chosen Discussion up there!
Answer when you can! =]

[Dr-Pete]

I'd say it's a matter of risk. If you're on an e-commerce site, for sample, where the risk of a page having URL-based duplicates is high, a pre-emptive canonical can make sense. In a perfect world, I agree with Alan - it's better not to need them. I've just rarely seen that perfect world on large sites.

"Landing pages" is a loaded term, though, because landing pages can often have tracking parameters (such as affiliate IDs) and other URL modifications. Some landing pages are a perfect storm of dupe content. So, it's really situational.

[seomasterbrasil]

Thanks for the attention Peter.

I understand your point about the Homepage.

But what about other pages? Landing pages with canonical to it self?

It seems to me meaningless, or worse, lowering trust, like Bing seems to do, in the link Alan wrote above.

[Dr-Pete]

I think it's good for some pages, especially the home-page, because you can naturally have so many variants ("www" vs. non-www, for example). It's a lot easier to pre-emptively canonicalize them than 301-redirect every URL variant that might pop up over time.

While Alan's concerns are technically correct, I've never seen evidence that either Google or Bing actually devalue a page for a self-referencing canonical. For Google, the risks of duplicates are much worse than the risk of an unnecessary canonical tag, IMO. For Bing, I don't really have good data either way. More and more people use canonical proactively, so I suspect Bing doesn't take action.

I don't generally use it site-wide, unless needed, but I almost always recommend a canonical on the home-page, at least for now. Technical SEO is always changing.

[AlanMosley]

yes you are correct,

The only good thing about doing it is stopping scrapers, if they dont take them out, but i dont think this is much of a advanatge as I believ if you do get scraped it is likely that they will remove you canonical, if they dont, I believe that SE's will see that they have a site full of duplicate content and give the credit to you anyhow. I think that SE's get this correct most of the time.

And if you are using canonicals for a valid reason, you dont want Bing to ingnore them because you have misused them elsewhere. Even for 2%

[seomasterbrasil]

Thanks Alan,

So, what seems is that "self page canonical" has no clear or even any good points for taking the risk of doing it?

I'm more concerned about Google, once I'm from Brazil, and Google rules 98% of searches...

[AlanMosley]

When some one scrapes your site they take the canonical with them, pointing back to the original, so you still get credit. that is if they dont take it out.

But this is a miss use of a canonical, a canonical should not point back to the same page.

Bing for one has said that they will lose trust in your site if you do this, they will start to not trust all your canonicals, those that are there for a good reason.
http://www.bing.com/community/site_blogs/b/webmaster/archive/2011/10/06/managing-redirects-301s-302s-and-canonicals.aspx

Google have said that they can handle it.

But a canonical does not pass all the link juice, so a canonical to itself, does it leak link juice? google says that can handle it, but that does not mean there is not a leak in link juice.

I for one dont do it, bing has made it clear they dont like, and even though google have said they can handle it, it does not mean there is no down side.

[seomasterbrasil]

Thanks Stephen!

Can your talk more about the scrape? It was not too clear for me.

Sorry =]

[firstconversion]

Nothing bad and turns good when people scrape your content (it gets scraped with the canonical to your page) or you make a mistake with your information architecture (as things tend to point to the correct place)