How to do 301 redirects in Apache .htaccess, IIS, PHP, ASP and ColdFusion

Establish proper search-friendly 301 redirects to manage duplicate content issues and changes to your site's information architecture (URL structure) with the specific instructions for your server software below:

Apache Web Server .htaccess file
Microsoft IIS Web Server
PHP 4+
Microsoft Active Server Pages (ASP)
ColdFusion 3+

Apache Web Server .htaccess file

Apache .htaccess files let you override the Web server configuration on a per-directory hierarchial basis, and are instrumental in the creation of proper 301 redirects. For more information, consult the Apache .htaccess Tutorial and the Apache URL Rewriting Guide.

Single Page Redirect:

Redirect 301 /old/url /new/url

or

Redirect Permanent /old/ur /new/url

Canonical Hostname Redirect (non-www to www):

This solution will redirect any page requested via a non-www domain to the same URL with the www domain, and as such it can be placed in the DocumentRoot of your site and will be enforced globally:

RewriteEngine On

RewriteCond %{HTTP_HOST} ^domain\.com

RewriteRule (.*) http://www.domain.com/$1 [R=301,L]

Microsoft IIS Web Server

Note: these instructions require administrative access to IIS. If you do not have this access (e.g., if you have a shared hosting account on a Windows server), you should use one of the server-side scripting methods such as ASP or PHP given further below.

Single Page Redirect:

Open Internet Services Manager and right-click on the file or folder you wish to redirect.
Select the radio button "a redirection to a URL".
Enter the desitnation page for the redirect.
Check "The exact url entered above" and the "A permanent redirection for this resource".
Hit "Apply".

PHP 4 and PHP 5

Single Page Redirect:

<?php

header('HTTP/1.1 301 Moved Permanently');

header('Location: http://www.new-url.com/');

?>

Canonical Hostname Redirect (non-www to www):

<%
If InStr(Request.ServerVariables("SERVER_NAME"),"www") = 0 Then
      Response.Status="301 Moved Permanently"
      Response.AddHeader "Location","http://www." & Request.ServerVariables("HTTP_HOST") & Request.ServerVariables("SCRIPT_NAME")
      Response.End
End if
%>

Active Server Pages (ASP)

Single Page Redirect:

<%

Response.Status="301 Moved Permanently"

Response.AddHeader='Location','http://www.new-url.com/'

%>

Canonical Hostname Redirect (non-www to www):

This code should be inserted into a global include file or any ASP script which is executed for every page on the site before the page output begins:

<%
If InStr(Request.ServerVariables("SERVER_NAME"),"www") = 0 Then
	Response.Status="301 Moved Permanently"
	Response.AddHeader "Location","http://www."
		& Request.ServerVariables("HTTP_HOST")
		& Request.ServerVariables("REQUEST_URI")
	Response.End
End if
%>

ColdFusion

Single Page Redirect:

<cfheader statuscode="301" statustext="Moved permanently">

<cfheader name="Location" value="http://www.new-url.com/">

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