Wednesday, March 23, 2011

Canonical Web Pages - Web Pages With Highly Similar Content

It's common for certain types of sites to have pages with similar content. A canonical page is the preferred page of the pages with highly similar content.

For example, you could have Beatles albums listed by popularity or by albums on two pages:
www.example.com/beatles.php?sort=pop
www.example.com/beatles.php?sort=album

To a search engine, these are two different pages. The major search engines will eventually learn that they contain similar content and prioritize one - but you can control this by adding a tag in the <head> section of both pages.

<link rel="canonical" href="http://www.example.com/beatles.php?sort=pop" />

This basically allows you to tell Google - "Out of all the pages with this link, prioritize this link instead in search".

For more information, check out Google's explanation of Canonical Pages.

EDIT:
For those of you using Wordpress, Blogger, or most other popular blogging software, this is added automatically for you.

5 comments:

  1. Is there a plugin in Wordpress or Blogspot that will indicate the canonical tag automatically for every post? Thanks for the info.

    ReplyDelete
  2. Most blog software is already optimized for this - which is why it's so important to use the more well known blog software - Wordpress, Blogspot, etc. They take care of all the little things for years to come.

    Basically, Blogs don't need to specify a Canonical page because they just have one link anyway.

    Here's a more detailed explanation if you are curious:

    For most blog software, the posts just have one link. Even the Comment link uses the same link - it just has a #Comment after the link.

    # Tags are OK - Search Engines will see these as the same link.

    ReplyDelete
  3. If you do the prioritizing thing, are you still able to view both of the tags that show up when you search for it?

    ReplyDelete
  4. They shouldn't both show up in Google, if that's what you mean. Which is what you want - because of they both showed up in Google, then you know Google considers them separate pages.

    If Google considers them separate pages, any links to one don't count to the other's PageRank. You'd basically be splitting your PageRank in two :(

    But if you mean can USERS still use the functionality on the site, yeah it won't affect that. They will still be able to use both links.

    This tag only tells search engines what to do.

    ReplyDelete
  5. In fact, your website - http://www.xpirtdesign.com uses Canonical links already.

    Both in your "platinum seo pack 1.3.7", whatever that is (some sort of Widget or something?), and Wordpress itself add the Canonical tag to the header.

    I don't know what affect two Canonical tags have - I doubt that is hurting your SEO at all.

    Nice site, btw.

    ReplyDelete