Canonicalization has been talked many times on forums, blogs, and conferences. Today also, I am trying to focus on Canonicalization & duplication content, its impact on SEO, how to fix Canonical issue, myths about duplicate content etc.
Definition of Canonical by Google-
“A canonical page is the preferred version of a set of pages with highly similar content.”
Does Canonical URLs create duplicity issue for my website?
Yes, canonical versions of URL will considered as different pages with identical content.
For example- if your site has 3 versions of home page:
These 3 will be considered as duplicate content. There might be several consequences of it. Some of them are as follows:
Dilution of link popularity: If you have backlinks for different versions of URL (like 10 links for www version & 10 links for non www version) then it will dilute your link popularity. It will always be a good idea to get all the backlinks on only preferred version of your page so that it can get the complete link juice & can get more PR.
User-unfriendly URL in search results: If you have different versions of URLs then Google will show only one version which it feels the most appropriate for users in each given search, which may or may not be the version you’d prefer. For example, it can show your Home Page URL with some dynamic parameters or session IDs which may decrease usability.
Inefficient crawling: Do you really want Google to spend all time on your site to find the different versions of the same URL? I guess NO. If we will define the canonical versions/ preferred to Google then it will spend more time in searching new pages (deep level pages) of your site. Isn’t it good?
How to fix canonical issue?
Google has suggested several ways by which we can tell Google about our preferred versions of URLs. Some of them are as follows:
301- Redirect: Add 301- redirect (A permanent redirect) from canonical URLs to preferred URLs.
This will notify Google to transfer your link popularity only to your preferred version of URL. 301-Redirect is very helpful in the situation when you are planning to transfer your site to a new domain or when you are planning to change your URLs structure to make them more search engine friendly.
Set preferred version by Google webmasters: You can easily specify non-www Vs www by Google webmasters tool. There is one “Setting” option in “Site Configuration” section of Dashboard where you can define your preferred domain.
Internal Linking: Try to use only your preferred URL for internal linking.
Robots.txt: Disallow the pages (which you considers duplicate or identical) by Robots.txt. This will help Google to crawl only the best version of your pages.
rel=”canonical” attribute: This new option lets site owners suggest the version of a page that Google should treat as canonical. We can specify the canonical version of page by creating a <link> element. For more info please visit this URL- http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=139394
Keep the URLs as clean as possible by removing unnecessary parameter.
Definition of Duplicate Content by Google-
“Duplicate content generally refers to substantive blocks of content within or across domains that either completely matches other content or is appreciably similar.”
Many webmasters have misconception that they can be penalized by Google for duplicate content on the website, however Google does not take any action on the ground of duplicity until unless content is deliberately duplicate across domains in an attempt to manipulate search engines rankings or win more traffic. Google might remove your site from search engines if they found your website engagement in deceptive practices.
Which type of content will not be considered as duplicate content?
- Discussion forums that can generate both regular and stripped-down pages targeted at mobile devices
- Store items shown or linked via multiple distinct URLs
- Printer-only versions of web pages
I have multiple domains for my website for different countries. Is it ok? Will it create the duplicity issue?
No, if you have different domains for different countries with targeted content then it will not create the duplicity issue. It will be good for you to define the geographic location for each website (by Google Webmasters tool). It will help Google to find the most relevant domain for a specific query for a specific country search.
For more information, you can watch video from Greg Grothaus.
December 18th, 2009 at 2:24 am
Nice information. Keep up the good work.