A redirect consists of a status code that starts with a 3 that informs a browser to transfer a visitor from one domain to another. The main SEO purpose of a redirect is to provide one copy of each page to search engines. The redirect can prove successful if that when you type in your previous URL you are automatically redirected to your new URL. You can verify this by looking at your browser’s address bar.
One of the most popular forms of a redirect is a 301 redirect where you tell search engines that your site has permanently moved to another location. You can refer to one of my previous blogs to get more information regarding the uses and functions of 301 redirects. According to Wikipedia, the other core HTTP status codes for redirects are as follows:
302 Found: This is the most popular redirect code, but also an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was “Moved Temporarily”), but popular browsers implemented it as a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to disambiguate between the two behaviours. However, the majority of Web applications and frameworks still use the 302 status code as if it were the 303.
303 See Other (since HTTP/1.1): The response to the request can be found under another URI using a GET method.
304 Not Modified: Indicates the resource has not been modified since last requested. Typically, the HTTP client provides a header like the If-Modified-Since header to provide a time against which to compare. Utilizing this saves bandwidth and reprocessing on both the server and client.
305 Use Proxy (since HTTP/1.1): Many HTTP clients (such as Mozilla and Internet Explorer) don’t correctly handle responses with this status code, primarily for security reasons.
306 Switch Proxy: No longer used.
307 Temporary Redirect (since HTTP/1.1): In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.
This is a sample of a HTTP response that uses the 301 “moved permanently” redirect:
HTTP/1.1 301 Moved Permanently
Location: http://www.example.org/
Content-Type: text/html
Content-Length: 174
<html><head>
<title>Moved</title>
</head><body>
<h1>Moved</h1>
<p>This page has moved to <a href=“http://www.example.org/”>http://www.example.org/</a>.</p>
</body></html>
A redirect is also very useful to ensure that you are not placing duplicate content on your website. Although URL’s may appear to go to the same site (www.boomyeah.net, http://www.boomyeah.net & www.boomyeah.net/index.php), the major search engine robots view these as different pages with the same content. This could create duplicate content penalties against you. Therefore, you need to ensure that your URLs are consistently identical.