Did you know that your website can either be non www or www, but it should never be both. Using either www or non www doesn’t change anything but using www is the standard and is also the most popular. The important thing with this is that you only have to use one and never both.
Why shouldn’t you use both on your website so people can choose?
If you are going to use www and non www to access your website, you will have two different versions of your site. If you have both they will be seen as duplicated content and this is a big no no for SEO and could end up hurting your rankings on Google. Each version (www or non www) can attract links and some will be linked with the non www and some links will use the www version. This will weaken your overall link value.
How to check your website?
It’s easy to check your website if it uses www or non www. Go to your browser and type your domain name starting with www and then another browser window using non www. Does the website redirect to a certain one or are both active? If there are a redirect in place and you are redirected to one, your website is perfect. If your website is not redirecting on either one, it’s crucial to get a redirect in place so that only one version exist.
To fix the redirect, you will have to use a 301 redirect from the non www to the www version or other way round. The reason for a 301 redirect is so that you don’t lose any value from the site you are redirecting from and that the existing value of that domain carries over to the site you are redirecting to. A 301 redirect is classified in browser terms as a permanent redirect.
Next, visit your Google Webmasters Tools account where your website is listed and choose to select either the non www or www version (the one you chose) as your preferred website. This will ensure that Google only crawls the domain you have chosen to use.