It was February 2009 when the concept came in the picture, the rel=canonical link element was introduced. This post/article illustrate that how you can use canonical URLs to improve link and ranking for content reachable through multiple URL structures or via syndication.
Some canonical URL examples and use cases are
|Some dynamic URL referring same page||https://www.yourblog.com/products?category=dresses&color=green
|Saving same post under multiple categories or tagging them.||http://blog.yourblog.com/dresses/green-dresses-are-awesome/
|Your server configuration is in such way that the same content for the www subdomain or the HTTP protocol.||http://yourblog.com/green-dresses
|Using others site blog post content in your site after acquiring explicit permissions.||https://news.yourblog.com/green-dresses-for-every-day-123.html (syndicated post)
https://blog.yourblog.com/dresses/green-dresses-are-awesome/234/ (original post)
Why Canonical Problem Happens?
While publishing your post using any hosting platform like WordPress, Joomla, Tumbler etc. You can map your post with multiple tags/categories, even the same page is saved using page Id’s.
This is a situation which confuses and alerts search engines of duplicate contents possibility. Although they are not duplicate but different URL redirecting page to same content is not acceptable by search engines.
A simple example –
A page opened using URL–
showing same content.
Why the Canonical Setting is important for your Blog?
To save your blog getting penalized. If happened, you will lose your search engine ranking and will never again get honor by search engines for better ranking.
How to apply Canonical setting?
If two versions have exactly same contents then you have to provide a link mentioning your main URL in the other page head section
Example <link rel=”canonical” href=”www.youblog.com/go-green/”>
Technically this is “merging” of the two pages into one from a search engine’s perspective. It’s kind of “soft redirect”, without redirecting the user directly refreshing the page.
This is linking of both URLs to the single canonical version of the URL.
This is a defensive option, just placing <link rel=”canonical” href=”www.youblog.com/go-green/”>
Into the main version of page itself www.youblog.com/go-green/
There is no harm doing so and can be done on your main page/post.
What Cross domain canonical
Using others website post content in your blog site.
Yes you can do that but beware to apply Cross domain canonical link the same way as I have explained above.
For this you require the explicit permission of the content owner, once granted you can use those article using rel=canonical link point right back at our original article. Clearly It is a win-win situation for both of them.
- How to set your preferred domain
- Indicating the preferred URL with the rel=”canonical” link element
- Using the sitemap to set preferred URLs for the same content
- Using the 301 redirects for URLs that are not canonical
- handling dynamic parameters
- How to Specify a canonical link in your HTTP header
- Prefer HTTPS over HTTP for canonical links if you have two protocols
Using the canonical in WordPress SEO
In the default installation of WordPress, You have to edit your post/page and then have to drag down to locate the setting to apply canonical value as shown below.
Why I am able to find the Canonical setting in my post/blog.
In free themes of WordPress these settings are not available, to use the setting either you need SEO plugin from Yoast or All in one SEO else you can purchase any SEO compatible theme like Genesis from studio press.
I am using Genesis Parallax Pro theme, You can change them here for the categories, tags and other taxonomy terms.