How to use custom error pages in Apache

Apache allows web administrators to replace default error pages with custom ones that match the site’s design. This enhances the user experience by providing more informative and visually consistent responses when an error occurs. Custom error pages can be used for various HTTP status codes such as 404 (Not Found) or 500 (Internal Server Error).

These custom pages are stored in web-compatible formats like HTML and are configured using the ErrorDocument directive in Apache’s configuration files. This setup ensures that users are directed to the appropriate custom page when an error happens, rather than seeing a generic error message.

Configuring these pages in Apache is straightforward. It involves editing the Apache configuration file, defining the path to the custom error pages, and then applying the changes by restarting the Apache service. This can be done for individual sites or across the entire server.

1. Launch terminal.
2. Open the Apache configuration file using your preferred text editor.

   $ sudo vi /etc/apache2/sites-available/000-mysite.conf

   Related: Location for Apache VirtualHost configuration

3. Add the ErrorDocument directive followed by the path to the custom error page.

   ErrorDocument 404 /custom_404.html

   This could be within a specific <VirtualHost> block if you want the custom pages to apply to a particular site, or outside of those blocks to apply server-wide.

4. Repeat the above step for any other error codes and sites you want to customize.
5. Save the configuration file and exit the text editor.
6. Check the configuration syntax to ensure there are no errors.

   $ sudo apache2ctl configtest

7. Restart the Apache service to apply the changes.

   $ sudo systemctl restart apache2

8. Test by accessing a page that triggers an error.