---
title: Why is running another CDN on top of Vercel not recommended?
description: Information about possible strategies when using a CDN on top of Vercel.
url: "https://vercel.com/kb/guide/why-running-another-cdn-on-top-of-vercel-is-not-recommended"
published: 2025-11-03
last_updated: 2026-01-08
authors: Justin Vitale
install_vercel_plugin: npx plugins add vercel/vercel-plugin
---

## Understanding the problem

The Vercel CDN was designed to carefully perform new releases of your application without downtime. Therefore, once a new production deployment is ready, we will purge our cache globally and replace the current deployment being served at your production domain with the new version.

If you use a CDN on top of Vercel, you may experience issues since our infrastructure cannot control those providers. A new release on Vercel can cause other CDNs to serve stale content referencing files that no longer exist. You can see an example of the issue below:

![Overview of possible issues sites using another CDN on top of Vercel may introduce to users.](https://images.ctfassets.net/hjgychtc108g/4lMu8AHVdCp9rP7uEzmthN/c165c77acbc12737490ed461c4329f40/swimlanes-053b18bb5dcec8a714f9c9c8f9ae5ae7.png)

A common symptom of the issue described above can be an increase in errors reported by your users after a production deployment is created. The stale HTML is returned by the 3rd party CDN but other assets were purged from it, returning a 404. For that reason, we recommend users to either configure the 3rd party CDN with a very short TTL in the cache or disable it completely.

For more information, see [Can I use a proxy on top of my Vercel Deployment?](https://vercel.com/guides/can-i-use-a-proxy-on-top-of-my-vercel-deployment)

## More Vercel CDN guides

- [How to revalidate Sitecore pages on publish with Next.js](/kb/guide/update-sitecore-content-manually): Learn how to use a Sitecore Experience Edge webhook and Next.js revalidatePath to refresh cached Sitecore Content SDK pages after each publish.
- [How to reduce Vercel Image Optimization costs](/kb/guide/reduce-image-optimization-costs-on-vercel): Learn how to reduce Vercel Image Optimization costs in Next.js by tuning cache TTLs, image sizes, formats, and quality. Diagnose high image transformation count and verify savings using the Vercel Dashboard.
- [Can I use a proxy on top of my Vercel Deployment?](/kb/guide/can-i-use-a-proxy-on-top-of-my-vercel-deployment): General information about using an external proxy to serve a Vercel Deployment.