Redirects can be used for a variety of reasons, but it’s important to consider which type of redirect works best from an SEO point of view. Implementing the wrong type of redirect can have a negative impact on your rankings and prevent old pages from passing on their full link value.
Two main types of redirect
Permanent redirects are commonly used when redesigning websites and when pages have been deleted for good. The key benefit to this type of redirect is that it transfers all of the historical data (PageRank, link popularity, etc.) to your new URL. 301 redirects are considered to be the most SEO friendly.
The 302 redirect is a temporary redirect. It commonly used to cover short term changes to websites (e.g. under construction pages when changes are being made). 302 redirects do not transfer PageRank, link popularity, or any other SEO value to URLs.
Other Redirect Methods
Another form of redirect which is surprisingly common amongst webmasters involves registering one or more additional domain names and then pointing this to the DNS servers of your main website. Again, this practise is not considered SEO friendly as search engines can penalise you for duplicate content.
Checking your redirects
There are a number of free tools which allow you to check the type of redirect used on your website. A Google search for “Redirect Checker” lists a number of tools you may like to try.
These should be able to tell you which redirect method you are using and whether this is considered to be SEO friendly.