Question: When should you use a 301 redirect?

A 301 redirect is a permanent redirection from one URL to another. It is used primarily for the following purposes:

1. URL Changes: If a webpage's URL has been changed (e.g., due to a site redesign or a move to a new domain), a 301 redirect ensures that users and search engines are directed to the correct page.

2. Merging Websites: When two websites are combined into one, 301 redirects can be used to direct traffic from the old URLs to the relevant pages on the new site.

3. Canonicalization: This involves redirecting multiple URLs that serve the same content to a single preferred URL. It’s useful for avoiding duplicate content issues and consolidating link equity to one URL.

4. Secure Protocol Shifts: When moving your site from HTTP to HTTPS, 301 redirects are necessary to ensure all requests to the insecure version are automatically redirected to the secure version.

5. Domain Name Change: If you're changing your domain name, 301 redirects can help preserve your search engine rankings by informing search engines that the old URL is permanently replaced by a new one.

Implementing a 301 Redirect

The implementation of a 301 redirect varies depending on the server environment. Here are examples for Apache and Nginx servers:

Apache (using .htaccess):

Redirect 301 /oldpage.html /newpage.html

Alternatively, using mod_rewrite in .htaccess:

RewriteEngine On
RewriteRule ^oldpage\.html$ /newpage.html [R=301,L]

Nginx:

server {
    server_name oldsite.com;
    rewrite ^/(.*)$ http://newsite.com/$1 permanent;
}

It is crucial to test your 301 redirects after implementation to ensure they work as expected without breaking other parts of your site. Using web tools like redirect checker can help verify that the status code for each redirect is correct.