PHP Domain Redirect Principles and Common Implementation Methods Explained

M66 2025-07-07

PHP Domain Redirection Principles and Implementation Methods

With the rapid development of the internet, the number of websites continues to grow, and sometimes we need to redirect the domain of a website. PHP, as a server-side scripting language, provides an easy way to implement domain redirection. This article will introduce the principles of PHP domain redirection and common implementation methods, along with code examples.

Domain Redirection Principles

Domain redirection essentially involves processing requests on the server side to redirect users from one domain to another. In PHP, this is typically done by setting the Location header in the HTTP response. When the browser receives a response with a Location header, it will automatically redirect to the specified URL.

Common Methods to Implement Domain Redirection in PHP

Method 1: Using the header() function for redirection

PHP's header() function can be used to send raw HTTP header information. By setting the Location header, you can redirect a user's request to a new domain.

<?php
// Set the target URL
$redirect_url = "http://www.newdomain.com";
 
// Send 301 permanent redirect
header("HTTP/1.1 301 Moved Permanently");
header("Location: $redirect_url");
exit;
?>

Method 2: Using 301 Redirect for SEO

Another common method of redirection is to use a 301 permanent redirect. This method not only correctly redirects user requests to the new domain but also informs search engines that the old URL has permanently moved to the new address. Using 301 redirects is SEO-friendly and helps maintain a website's search ranking.

<?php
// Set the target URL
$redirect_url = "http://www.newdomain.com";
 
// Send 301 permanent redirect
header("HTTP/1.1 301 Moved Permanently");
header("Location: $redirect_url");
exit;
?>

Method 3: Using the .htaccess File for Redirection

In addition to implementing redirection in PHP code, you can also use Apache's .htaccess file to perform domain redirection. By creating or editing the .htaccess file in the root directory of your website, you can add the relevant redirection rules to automatically redirect users to the new domain.

RewriteEngine on
RewriteCond %{HTTP_HOST} ^olddomain.com [NC,OR]
RewriteCond %{HTTP_HOST} ^www.olddomain.com [NC]
RewriteRule ^(.*)$ http://newdomain.com/$1 [L,R=301,NC]

Conclusion

Through the three methods introduced in this article, you can flexibly choose the best domain redirection solution for your website's needs. Whether using the header() function, 301 redirects, or the .htaccess file, these methods help achieve domain redirection, improving both user experience and SEO performance.