Redirections and Search Engines
In this post let’s briefly see about what Search Engine understand about the redirections and based on that how it works.
What is the background process behind displaying a webpage in a browser?
A request will be sent to the server to retrieve a specific page, server will respond with HTTP Server header status code (200, 301, 302, 304, 307, 404, and 410).
200 – Ok. The request has succeeded (This must be server header status code for all our viewing pages.)
404 – Not Found. (The server has not found anything matching the Request)
Above are the server header codes and still many to be listed. To know more about this Check Here
Now let’s get back to redirection,

Redirection
301, 302 and 307 which we are calling as redirection types also server header values.
301 Redirection: This is called permanent redirection and it should be done when we permanently moving the location.
302 or 307 Redirection: According to “HTTP 1.1” temporary redirection is 307 but nothing defined to search engine yet. So still we need to use 302 for temporary redirection.
What search engine can understand from 301 redirection?
User has permanently moved the location to the new URL. Also Google will automatically remove the old URLs from index and include new URLs. If you watch closely, at certain point both the old and new URL will be in index, later it will take away the old URLs. Google will shift all the weightage to the new URL which it has given for the old URL.
What search engine can understand from 302 (or 307) redirection?
User has just moved the website temporarily and it will be back to the old URL after sometime. In this case Google will not index the new URLs; it will keep the old URLs alone in index.
302 example case:
Your website is down and you cannot make it live quickly. You are having another domain with similar theme, till your website get ready you can use this redirect to point the working website. So that your domain weightage will remain as it is till you remove this redirection.
So there is nothing like Search Engine Friendly Redirection. Use right script at right situation. Thats it!











With a 302 redirect, the search engine will usually keep the old URL, but there is a danger that if some other site links to the new (or temporary) URL, that *both* URLs will end up being indexed.
There is a difference in handling of redirects between Google, Yahoo and Live, and there are some differences depending on whether the redirect is internal to the domain or is to another separate domain.
In the case of a cross-domain 302 redirect, Google prefers to keep the target URL, not the source URL, these days. In the past, they did the opposite and that caused a *lot* of problems.
@ g1smd, thanks for sharing additional info…
Using a 302 redirect instead of a 301 can cream your site with duplicate content penalization.