# Content Delivery Network recommendations

This article provides information and best practices on using Content Delivery Network (CDN) with Umbraco Engage.

## Pages (HTML)

Do not cache pages on the CDN level. Umbraco Engage is based on serving a unique page to every (returning) visitor. By enabling page caching every visitor will be assigned the same Umbraco Engage ID and Analytics, A/B testing, and Personalisation will not work correctly.

### Cache static files (CSS and JavaScript)

It is possible to cache static CSS and JavaScript files. Refer to the documentation of the CDN provider for the best-practice setup.

### Media files (Umbraco /media folder, images, and PDFs)

It is possible to cache `/media` files. Refer to the documentation of the CDN provider for best-practice setup.


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.umbraco.com/umbraco-engage/getting-started/for-developers/content-delivery-network-recommendations.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.