How can you manually diagnose the canonical problem

[Nightwing]

Good Monrning from snow dusted minus 3 degrees C Wetherby UK...

Is there a quick way to diagnose wether or not a website has a canonical problem or not?

So far Ive been doing this for example: Typing a full web address then one without the w's and seeing if a 301 redirect has been set up. But I'm not confident this is the best way to diagnose if there is a canonical problem with a site.

I would like to ad that I want to see if a canonical problem exists with any site and webmanster tools is not available.

Any insights welcome

[Vahe.Arabian]

Use screaming frog.

Using the free version it will crawl up to 500 pages. For each page it will then provide the status code i.e. 302, 400 e.t.c  That way you can determine if there are any page issues.

In general, Google Webmaster Tools is your best bet of showing a sites cannonical issues. Otherwise you can also try SEOMoz's pro tools ;0

Hope this helps.

[Thommas]

Morning Nightwing

We also had some snow here in B'ham but it's almost gone now.

If you want to be sure then simply implement 301 redirects. When doing a manual check, like the one you've mentioned above, you can look at your SEOmoz toolbar and you will often see a difference in PA of different versions of your page.

[ASOS]

Hey Nightwing

I think you need to be careful here. A 301 is a re-direct whereas a canonical is telling Google, Bing etc to treat this page as a duplicate and not index it.

To quote Google: "A canonical page is the preferred version of a set of pages with highly similar content."

See Matt Cutts and all his beauty explain here: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=139394

A canonical won't re-direct the page like a 301, the page still exists, it's just that search engines will remove it from SERPs.

As long as the code is all set up right, the only way to check for a canonical is working is to review the code.....and it should also drop out of the SERPs too.

Hope this helps.

Stay warm

[Thommas]

Keep in mind that  rel=canonical is more of a suggestion than a command.

[ASOS]

A suggestion that all major search engines obey. We used it massively and it is 100% listened to by search engines.