Assets CDN vs. CDN Edge Cache: What’s the Difference?

RunCache includes two CDN features that serve different purposes:

Assets CDN rewrites static asset URLs so files such as images, CSS, JavaScript, and fonts can be served through a CDN.
CDN Edge Cache stores and serves complete HTML pages from an edge provider.

This guide explains how the two features differ, when to use each one, and how they can work together.

Assets CDN and CDN Edge Cache Compared

	Assets CDN	CDN Edge Cache
What it does	Rewrites asset URLs in your HTML so they point to a CDN hostname	Gets a provider to cache and serve your HTML pages
What it caches	Nothing. It changes URLs only	Complete webpages, at the provider’s edge
Providers	BunnyCDN, Custom CDN	Cloudflare Page Cache, Cloudflare APO
Dashboard tab	Assets CDN	CDN Edge Cache
Needs an API account	BunnyCDN requires account credentials. Custom CDN requires a CDN hostname.	Yes. Cloudflare credentials are required.
Verify button	Verify CDN	Verify Edge Cache

How Assets CDN Works

Assets CDN rewrites static asset URLs so they use your configured CDN hostname instead of your site hostname.

For example, URLs for images, stylesheets, and scripts can be rewritten from your site domain to the CDN domain. The CDN then retrieves the files from your origin server as needed.

The Choose a CDN provider block, subtitled Enable one provider at a time to rewrite your static asset URLs through a CDN, with two cards side by side: BunnyCDN, described as Accelerate your media files delivery using BunnyCDN's global network, and Custom CDN, described as Bring your own CDN hostname and let RunCache rewrite asset URLs to it

The Assets CDN settings let you choose between BunnyCDN and a custom CDN hostname.

RunCache applies the CDN hostname to supported static asset URLs generated by WordPress.

Assets CDN doesn’t control full-page caching. Its purpose is to rewrite asset URLs and, where supported, purge cached assets from the CDN.

How CDN Edge Cache Works

CDN Edge Cache stores complete HTML pages at the edge provider. Visitors can then receive a cached page from the provider without the request reaching your origin server.

Unlike Assets CDN, this doesn’t rewrite the asset URLs in your HTML.

The Choose an edge cache provider block, subtitled Cache complete webpages at the CDN edge. Only one edge cache provider can be enabled at a time, with two cards: Cloudflare Page Cache, available on all Cloudflare plans including Free, and Cloudflare APO, requiring an active APO subscription for the domain

RunCache supports Cloudflare Page Cache and Cloudflare APO for CDN Edge Cache. However, only one edge cache provider can be enabled at a time.

RunCache manages edge caching in two main ways:

It configures the selected provider through its API. For Cloudflare Page Cache, RunCache creates the required cache rule. For Cloudflare APO, RunCache enables APO for the configured hostname.
It sends response headers that tell the provider whether a response can be cached.

CDN Edge Cache doesn’t rewrite URLs within the page content.

Using Assets CDN and CDN Edge Cache Together

You can enable one Assets CDN provider and one CDN Edge Cache provider at the same time.

Within each feature, only one provider can be active. Selecting a different provider replaces the previously selected provider for that feature.

Assets CDN and CDN Edge Cache operate independently, so you can use both features together if required.

How Cache Purging Differs

When RunCache triggers a purge, Assets CDN and CDN Edge Cache clear different types of cached content.

BunnyCDN can purge cached asset files from its pull zone.
A custom CDN hostname is not purged automatically because RunCache doesn’t have access to the provider’s API.
CDN Edge Cache purges cached HTML pages from Cloudflare.

Changing the Assets CDN hostname or enabling or disabling Assets CDN also clears the local page cache. This prevents existing cached HTML from continuing to reference the previous asset hostname.

Changing CDN Edge Cache settings doesn’t trigger the same local page-cache purge.

Choose the Right CDN Feature

Use the Assets CDN to load static files such as images, CSS, JavaScript, and fonts via a CDN hostname.
Use CDN Edge Cache if you want complete HTML pages to be cached and served from Cloudflare.
Use both if you want CDN delivery for static assets and edge caching for HTML pages. You will need to configure the two features separately.

Related: the extension list the rewriting engine consults, choosing between the two edge providers, reading the response headers, and the reported case where a missing extension broke images in emails.

For more information about provider-specific features, see the Cloudflare Cache Rules documentation and Bunny.net documentation.