How to Enable CDN Rewrite in WordPress

Why You Need It

A CDN (Content Delivery Network) caches your static files on servers around the world. Serving files from a CDN closer to the visitor reduces load time and bandwidth costs.

How to Enable this Feature

Step 1: Navigate to Settings

Click into the Classic Monks plugin settings, then the Performance tab, CDN subtab.

Step 2: Enable the Feature

Toggle on the feature.

Step 3: Save and Test

Click Save Changes. Test on the frontend.

Common Use Cases

Global audience sites

Sites with visitors worldwide benefit from CDN caching. A visitor in Tokyo gets the file from a Tokyo server instead of your US-based origin server.

High-traffic sites

For sites with millions of page views, a CDN reduces origin server load and bandwidth costs.

Troubleshooting

The feature is not taking effect

Cause: The toggle is off, or a caching plugin is serving the old page.
Fix: Verify the toggle is on. Clear all caching layers.

The feature breaks another plugin

Cause: Another plugin depends on the functionality that this feature disables.
Fix: Disable this feature if it breaks another plugin.

Developer integration

This feature registers 5 WordPress hooks in cdn-enabler.php:

Filters:

• the_content calls cm_cdn_enabler() (Rewrites content URLs to CDN (priority 100))
• wp_get_attachment_url calls cm_cdn_enabler() (Rewrites attachment URLs to CDN)
• template_directory_uri calls cm_cdn_enabler() (Rewrites theme directory URL to CDN)
• script_loader_src calls cm_cdn_enabler() (Rewrites script source URLs to CDN)
• style_loader_src calls cm_cdn_enabler() (Rewrites style source URLs to CDN)

// Hooked in cdn-enabler.php
add_filter( 'the_content', 'cm_cdn_enabler' );

The feature modifies WordPress behavior by registering or removing hooks. Disabling it reverses those changes and WordPress returns to its default behavior.

Before you enable this feature

1. Test on staging first to verify no conflicts with your theme or other plugins
2. Check dependent plugins that may rely on the functionality being modified
3. Monitor after enabling for any unexpected behavior on the frontend

How it works under the feature

This feature runs during the WordPress initialization phase. When enabled, its PHP code registers hooks that modify specific WordPress behaviors. The changes are non-destructive and reversible.

No database schema changes are made. The feature state is stored as a boolean value in the wp_options table and can be toggled at any time from the admin settings.