---
title: "Caching recommendations for Acquia Edge"
date: "2024-02-14T06:18:38+00:00"
summary: "Optimize your Acquia Edge CDN performance with expert caching recommendations. Learn how to set Edge and Browser Cache TTLs, choose cache levels, and efficiently update cached content for faster website delivery."
image:
type: "page"
url: "/acquia-cloud-platform/add-ons/edge/caching-recommendations-acquia-edge"
id: "af4b143a-b98f-4b65-b709-3dd46fc50fed"
---

Acquia recommends the following defaults for page caching rules in Edge CDN:

*   **Edge Cache TTL** (Time To Live): 1 minute
*   **Browser Cache TTL**: `Respect Existing Headers`

`Respect Existing Headers` will honor the user-defined `Expires` and `Cache-Control` headers. For more information, see [Edge and Browser Cache TTL](https://developers.cloudflare.com/cache/about/edge-browser-cache-ttl).

On occasion, an application may require a shorter **Edge Cache TTL** lifetime. If you reduce the amount of your **Edge Cache TTL**, be sure to change the **Browser Cache TTL** to the same value.

Edge CDN doesn’t enable **Edge Cache TTL** until the cache level is set. Select from the following available cache level options:

*   **Standard**: This level is the recommended starting point, and is suggested for websites with frequent content updates, and a need for visitors to be displayed new content with low delay.
*   **Cache Everything**: Select this option if you already know your website needs a greater level of caching.

You should also configure [Page Cache Maximum Age](/acquia-cloud-platform/performance/varnish/drupal) (the amount of time assets are cached in Varnish® and Drupal) to your desired value, typically 30 minutes to one day. Edge CDN will contact Varnish at most once per minute for updated copies of that asset.

Updating cached content before expiration
-----------------------------------------

If your content or assets have changed at origin (in your Drupal website), and you must update the cached copies of these assets before the [Page Cache Maximum Age](/acquia-cloud-platform/configuring-drupal-cache-settings-varnish "Configuring Drupal cache settings for Varnish") expiration date, Acquia recommends you use the [Acquia Purge](https://www.drupal.org/project/acquia_purge) module.

After configuration, the Acquia Purge module will cause content updates to purge selected portions of Varnish cache. The next time Edge CDN requests the asset from Varnish, it will receive the newly updated content.

Important

Due to API limitations preventing website visitors from viewing updates to content, Acquia does not recommend using the [CloudFlare Purge (cfpurge)](https://www.drupal.org/project/cfpurge) module.

Cache tags on Acquia Edge
-------------------------

When purging caches on Edge CDN using the API or the dashboard, the `Cache-Tag` header (including whitespace and commas) must not exceed 255 bytes in total length after the header field name. If the supplied `Cache-Tag` header exceeds 255 bytes in length, only the tags in the first 255 bytes will be purged.