How To Redirect From Non-WWW To WWW In Apache?

Using the Redirect Directive

The Redirect directive in Apache is a simple way to redirect non-www to www URLs. To use it, add this line to your Apache configuration file:

Redirect permanent / http://www.example.com/

This tells Apache to redirect all requests to the www version of your domain. The 'permanent' keyword means a 301 (permanent) redirect, which is good for SEO.

curl -I http://example.com

Configuring Virtual Hosts for Redirection

Setting up separate virtual hosts for www and non-www versions of your website gives you more control over redirection. Here's how to do it:

1. Create a virtual host for the non-www version:

<VirtualHost *:80>
    ServerName example.com
    Redirect permanent / http://www.example.com/
</VirtualHost>

2. Set up a virtual host for the www version:

<VirtualHost *:80>
    ServerName www.example.com
    # Your main server configuration goes here
</VirtualHost>

This setup keeps the URL structure during redirection. For example, if someone visits 'http://example.com/page.html';, they will go to 'http://www.example.com/page.html';, keeping the original path and query parameters.

Steps to Configure Apache

To set up the Apache redirect from non-www to www:

1. Open your Apache configuration file. Common locations:

   • /etc/apache2/apache2.conf (Ubuntu/Debian)
   • /etc/httpd/conf/httpd.conf (CentOS/RHEL)

2. Add this code to your configuration file:

<VirtualHost *:80>
    ServerName example.com
    Redirect permanent / http://www.example.com/
</VirtualHost>

<VirtualHost *:80>
    ServerName www.example.com
    # Your main server configuration goes here
</VirtualHost>

Replace "example.com" with your domain name.

3. Save the changes.

4. Restart Apache to apply the changes:

   • sudo systemctl restart apache2 (Ubuntu/Debian)
   • sudo systemctl restart httpd (CentOS/RHEL)

<VirtualHost *:80>
    ServerName example.com
    ServerAlias *.example.com
    Redirect permanent / http://www.example.com/
</VirtualHost>

Testing the Redirection

After setting up the redirect, test it:

1. Open a web browser and enter your non-www URL (e.g., http://example.com).

2. Check if it redirects to the www version (http://www.example.com).

3. Test different pages and subfolders to make sure the redirect works for all URLs.

4. Use curl to check the HTTP response:

curl -I http://example.com

Look for a 301 status code and the new location in the response headers.

If the redirect doesn't work, check these issues:

• Make sure you restarted Apache after making changes.
• Check the Apache error logs for configuration mistakes.
• Verify that mod_alias is enabled.
• If using .htaccess, make sure Apache allows .htaccess overrides.

By following these steps and testing, you can set up a working non-www to www redirect in Apache.

Using mod_rewrite for Redirection

The mod_rewrite module in Apache offers a way to handle URL redirection. To use it for non-www to www redirection, add these lines to your Apache configuration:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

This configuration turns on the rewrite engine, checks if the requested host doesn't start with "www.", and then redirects to the www version if it doesn't.

Pros of using mod_rewrite:

• Flexible for complex redirection rules
• Can handle various URL patterns and conditions

Cons of using mod_rewrite:

• More complex syntax compared to the Redirect directive
• Can be slower for simple redirections
• Requires the mod_rewrite module to be enabled

RewriteLog "/path/to/rewrite.log"
RewriteLogLevel 3

.htaccess File Approach

For shared hosting environments or when you can't access the main Apache configuration, you can use a .htaccess file for redirection. Create or edit the .htaccess file in your website's root directory and add:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

This achieves the same result as the mod_rewrite method in the main Apache configuration.

Considerations for shared hosting:

• Make sure .htaccess files are allowed on your hosting plan
• The .htaccess file is read on every request, which can impact performance
• Changes in .htaccess take effect immediately without restarting the server
• Be careful with syntax errors, as they can make your site inaccessible

When using .htaccess, test your changes carefully to avoid disrupting your website's functionality.