The Vercel Edge Network sits in-between the internet and your Vercel deployments. This type of network topology is sometimes called a Content Delivery Network or CDN.
The Vercel Edge Network has many responsibilities, but most importantly, it is responsible for routing requests to the correct Serverless Function or Static File output of your Builds. The Vercel Edge Network is a CDN with the ability to execute functions at the edge.
In order to route requests as fast as possible, the Edge Network is running in dozens of locations across the world. In all of these locations (called Regions), you can create Deployments that create Builds outputting Serverless Functions and/or Static Files.
In turn, the Edge Network will automatically forward incoming requests to the closest location in which your Serverless Function is running (Static Files are always distributed across the whole network, thus not location-specific).
In the event that the Serverless Function of your deployment is not created in the requested region, the request is forwarded to the closest region that contains your deployed Serverless Function.
In order to help you decide the best region for your Serverless Functions, we recommend considering the following questions:
- Where is your database located?
- Where is your API located?
You will then deploy the Serverless Functions as close as possible to these locations for the maximum speed of execution. However, please note that the ability to choose a region and the number of possible regions depends on your plan as described in the article below.
Please refer to this Support Article for more details.
The Vercel Edge Network caches your content at the edge in order to serve data to your users as fast as possible.
Vercel supports streaming responses from Edge Functions. You can use the Streams Web API in your Edge Function, which enables you to return data from remote sources incrementally rather than all at once. Check out our Edge Function Streaming guide to learn more.
Aside from routing your requests to the correct destination, the Edge Network also takes care of a few other important aspects of a working Deployment:
All of these actions are performed automatically with careful attention to performance (ensured by our choices of technology). In turn, we highly recommend not implementing SSL termination or compression in your own code, as it would be unnecessary.
The Edge Network supports the following protocols (negotiated with ALPN):