Does Google Ignore Canonical Tags?

[internetheaven]

Just fixed up a site that had loads of canonical errors, but Google had indexed all the pages just fine over the past year? I thought canonicals were meant to be almost 301s?

[goodroi]

Canonical tags can be helpful but from my POV they are definitely not like 301 redirects. They are more of a helpful suggestion than a hard & fast rule. To make things even more complicated it seems Google & Bing differ greatly on how they want webmasters to use canonical tags.

[internetheaven]

To make things even more complicated it seems Google & Bing differ greatly on how they want webmasters to use canonical tags.

I was unaware of this. Any docs I can read on such?

[goodroi]

The last few months there have been several clarifications via official blog, video and twitter.

Here are two links to get you started:
[bing.com...]
[googlewebmastercentral.blogspot.com...]

[deadsea]

As far as I can tell, the biggest difference between the bing and google canonical treatment is self-referential canonicals. Google says, "Its good practice". Bing says, "Don't do it, its like an infinite redirect to yourself".

[Planet13]

Bing is stupid...

[mark_roach]

Google says, "Its good practice". Bing says, "Don't do it, its like an infinite redirect to yourself".

Deadsea do you have a reference for those statements ?

In the two documents referenced by Goodroi. Google makes no comment (unless I have missed it) and Bing says :

"Pointing a rel=canonical at the page it is installed in essentially tells us “this page is a copy of itself. Please pass any value from itself to itself.” No need for that."

I read that as being harmless and pointless, but certainly not dangerous (as your infinite redirect statement implies).

[internetheaven]

Bing is stupid...

Bing is not a person. So which of the programmers, designers, formulators, administrators and/or management team behind Bing do you consider to be "stupid"?

I think Bing may have not thought through their stance properly, but I don't think anyone working on Bing is actually "stupid". Just like I don't think a child is stupid for shouting out something ridiculous. They're a kid, they'll hopefully learn.

Sadly, Bing has not taken to account that many other people LINK to sites with the wrong information or with broken coding.

e.g. http://www.example.com/file/index.php?soup=1
http://www.example.com/file/?hello
http://www.example.com/file/"anchor text</a>
http://www.example.com/file/default.php
http://www.example.com//file/
etc.

may all show the exact same information. Now, when someone is creating their site, they may have absolutely no idea that so many "stupid" people will link incorrectly. Having a canonical tag as a backup (when obeyed) is a great way to solve this issue without having to have hundreds, if not thousands, of pre-emptive htaccess 301s.

[Bewenched]

Bing would say that since IIS (aka Microsoft, aka Bing) is one that doesnt care about captilization, where as Google counts those pages separately.

example
www.example.com/Page.html
vs
www.example.com/page.html

[deadsea]

Google mentions the self-referential canonicals when they reply to the comments.

[Shatner]

In my experience Google not only pays attention to Canonical tags, it weights them very heavily.

It's probably the single most important thing you can do for Google on your pages.