Introduced by all search engines (Google, Yahoo & MSN) together in early 2009, a canonical URL tag is a tag code that you place in the HTML source of your page that tells Google and other search engines that this page is an identical copy of the URL placed in that tag.
What this means exactly is that Google will not consider it as a duplicate page and this page will not be ranking well as compared to its canonical URL in Google. Simply put this gives an indication to Google about your preferred version of the similar content pages on the same domain.
Here is the canonical tag code,
<link rel=”canonical” href=”http://www.seojunky.com/test-site.php” />
So where do you place the canonical URL tag in your code
Normally the canonical URL tag is placed in your <head> section of the duplicate content URL.
Canonical URL Tag vs a 301 redirect?
- Canonical URL tag is for search engines and not for the human site visitors which means you can still track unique visits to that page.
- The URL having a canonical URL tag gets indexed and has its slow ranking but it doesn’t disappear from the search engines as compared to a 301 redirect where the page is no longer ranking or visible to your visitors.
- You can make a 301 redirect to a different domain, but a canonical URL tag can only be referred to another URL on the same domain.
- Both 301 redirect and canonical URL tag transfer their link juice and other URL properties like page ranking, authority and related signals to the pointing URL.
Why use a canonical URL tag?
If you are using multiple pages of duplicate content on your domain for whatever reason (print version, a copy for PPC, or a different URL as your landing page), the best practice to follow is placing a canonical URL tag, as this tag tells search engines that you are not trying to duplicate different URLs and hence reducing the quality of your website due to repeated content, but rather, you are using these pages for certain purposes for your internet marketing strategy.
This way, search engines have to worry no longer about which page is the “real” page. So, instead of leaving a search engine to decide which of these multiple duplicate content pages needs to be indexed properly, you make this decision by putting a canonical URL tag and making things clear and smooth.
Canonical URL tag fair usage policy and SEO best practice:
- Canonical URL tag is used if you are using different URLs having the same content page (duplicate copy) for the purposes like running a PPC campaign, a print version of the same page etc. This sends signals to search engines on what version of a page you want them to consider during their ranking process.
- The pages with canonical URL tags must be similar to the page they are referring to. If not 100%, they have to be nearly 100% duplicate copies of the referring page. A small variation for the sake of use of that page in your print version or anything else you want to use that page is okay with search engines, but if you are using different content and putting a canonical URL tag, then it doesn’t serve the purpose and rather makes Google feel as if you were cheating, means you are using a non-relevant page to strengthen another page by giving signals to search engines that they are similar.