SEO Best Practice - 301 redirect and canonicalisation
Canonicalisation is often overlooked during the web development process, but it can have a negative effect on your website’s rankings in the search engines.
What is canonicalisation?
Basically, it is having multiple live urls for identical pages.
For example, if not set up properly, the home page of a site can often be accessed using different paths:
http://www.yourdomain.com.au
http://yourdomain.com.au
http://www.yourdomain.com.au/
http://yourdomain.com.au/
http://www.yourdomain.com.au/index.html
http://yourdomain.com.au/index.html
http://www.yourdomain.com.au/index.htm
http://yourdomain.com.au/index.htm
http://www.yourdomain.com.au/home.htm
etc...
So if unchecked, your home page alone can be floating in cyberspace in 8 different versions or more...
How could canonical urls have a negative impact on your search engine rankings?
Search engines basically regard every url as a different page. Their aim is also to provide relevant and useful search results, so they also want to prevent these results pages from being flooded with duplicate content. Whenever a search engine comes across identical content, especially from the same top level domain, it will simply choose which page to show in it’s results pages. But if you leave it up to the search engine, it might not be the optimal choice. You might prefer a specific version of your web site’s url for branding purposes etc.
Canonicalisation can ultimately have a negative impact on your search engine rankings, because if people are able to link to different url paths to a page, each instance of these pages will accumulate their own PageRank or TrustRank level. The possible max. So the max. weight your page relevance could have for search engines, is diluted. You are “leaking” valuable ranking points here...
However, if you redirect those incoming links to one, single url path to your home page, you can ensure you capture any link love people are sending your way, and your home page will ultimately have more weight and achieve better rankings in the results pages. Not only that, you can then redistribute this accumulated link juice from your home page, into your most important pages.
What redirect options would benefit your SEO strategy?
There are several redirects to choose from, and different ways of setting them up, mostly depending on the technology your web site uses.
There are client side and server side redirect solutions. (I would advise a server side solution.)
In this particular case, setting up 301 redirects offers the best solution.A 301 redirect is what’s called a permanent redirect.
For example, when the search crawler hits this page:
http://yourdomain.com.au/index.html - it will receive a response that the page has been permanently moved to to http://www.yourdomain.com.au/ . This way, if the search engines has previously indexed another version of your home page url, you can manipulate it, so it will use your preferred url path.
Google Webmaster Central offers the ability to inform the Google bot of your preferred url format: So there you have it, to canonicalise, or not to canonicalise... no longer a question.
with www. Or without. It’s a neat functionality, but it is insufficient in most cases, to clean up any canonical urls from their index.
