Edge Network Regions

Serverless and Edge Functions empower you to run code on-demand and at scale without setting up your own compute infrastructure. When people visit one of your API routes that uses a Function, the Function is invoked in a region on Vercel's Edge Network. If your Function depends on a database, and is invoked in a region far from that database, the response time will be slow.

You can select a region for your Functions to mitigate this issue.

Selecting a region for your Functions allows you to choose where your Serverless Functions are deployed, and where your Edge Functions are invoked. You can set a default Function region in your project's Dashboard settings on Vercel. Learn how in the section below.

The default Function region is Washington, D.C., USA (iad1) for all new projects. Many of the most popular database and infrastructure providers deploy to this region by default, so this ensures your Functions will deliver fast responses out of the box in most cases.

This default region will apply project-wide to Serverless Functions, and can be configured in your project's Dashboard settings on Vercel. Follow the instructions below to do so:

• Choose the appropriate project from your Dashboard on Vercel
• Navigate to the Settings tab near the top of the Dashboard page
• A set of options will appear on the left side. Select Functions.
• Use the Function Region dropdown setting to select which Edge Region you want to use as your project's default

The Function Region setting in a Vercel project's dashboard

We highly recommend selecting the region closest to the data infrastructure your Functions depend on.

Edge Functions are deployed globally and invoked in the region nearest to the user, unless otherwise specified.

Edge Functions are defined in JavaScript or TypeScript modules in your codebase. You can specify a Function's region by exporting a config object in its module. Add a regions key to the config object, assigning the ID of your preferred region as a string.

Here's an example of an Edge API Route with its region set to 'iad1', Vercel's region near Washington, D.C., USA.

import { NextRequest, NextResponse } from 'next/server';

export default (req: NextRequest) => {
  return NextResponse.json({
    name: `Hello, from ${req.url} I'm now an Edge Function!`,
  });
};

export const config = {
  runtime: 'experimental-edge', // this is a pre-requisite
  regions: 'iad1', // only execute this function on iad1
};

If you want your Function to always invoke in the region nearest to website visitors, use the all region. Doing so will cause your Function to deliver responses as fast as possible, unless it relies on a database far from the visitor's nearest Edge region.

In most cases, you should set your Serverless Function region using the Function Region setting in your project's Dashboard on Vercel. Follow the instructions above to do so now.

If you want to override your default region, you can do so in two ways:

• With your vercel.json configuration file. Add your region to the "regions" key. Learn more about adding regions in our vercel.json docs.
• With the Vercel CLI. Use the vercel --regions command in your project's root directory to set a region. Learn more about setting regions with the vercel --regions command in our CLI docs.

This is a list of all Vercel Edge Network regions. Follow the above instructions to deploy your Functions to one of our regions.

When you use the vercel dev CLI command to mimic your deployment environment locally, the region is assigned dev1 to mimic the Vercel Platform infrastructure.

If an Edge Region goes down, an application's traffic gets rerouted to another Edge Region.