Request headers

The following headers are sent to each Vercel deployment and can be used to process the request before sending back a response. These headers can be read from the Request object in your Vercel Function.

This header represents the domain name as it was accessed by the client. If the deployment has been assigned to a preview URL or production domain and the client visits the domain URL, it contains the custom domain instead of the underlying deployment URL.

This header contains a list of Edge regions your request hit, as well as the region the function was executed in (for both Edge and Serverless).

It also allows Vercel to automatically prevent infinite loops.

export function GET(request: Request) {
  const host = request.headers.get('host');
  return new Response(`Host: ${host}`);
}

This header is identical to the host header.

export function GET(request: Request) {
  const host = request.headers.get('x-forwarded-host');
  return new Response(`Host: ${host}`);
}

This header represents the protocol of the forwarded server, typically https in production and httpin development.

export function GET(request: Request) {
  const protocol = request.headers.get('x-forwarded-proto');
  return new Response(`Protocol: ${protocol}`);
}

The public IP address of the client that made the request.

If you are trying to use Vercel behind a proxy, we currently overwrite the X-Forwarded-For header and do not forward external IPs. This restriction is in place to prevent IP spoofing.

export function GET(request: Request) {
  const ip = request.headers.get('x-forwarded-for');
  return new Response(`IP: ${ip}`);
}

Enterprise customers can purchase and enable a trusted proxy to allow your custom X-Forwarded-For IP. Contact us for more information.

This header is identical to the x-forwarded-for header. However, x-forwarded-for could be overwritten if you're using a proxy on top of Vercel.

This header is identical to the x-forwarded-for header.

This header represents the unique deployment, not the preview URL or production domain. For example, *.vercel.app.

export function GET(request: Request) {
  const deploymentUrl = request.headers.get('x-vercel-deployment-url');
  return new Response(`Deployment URL: ${deploymentUrl}`);
}

A two-character ISO 3166-1 code representing the continent associated with the location of the requester's public IP address. Codes used to identify continents are as follows:

• AF for Africa
• AN for Antarctica
• AS for Asia
• EU for Europe
• NA for North America
• OC for Oceania
• SA for South America

export function GET(request: Request) {
  const continent = request.headers.get('x-vercel-ip-continent');
  return new Response(`Continent: ${continent}`);
}

A two-character ISO 3166-1 country code for the country associated with the location of the requester's public IP address.

export function GET(request: Request) {
  const country = request.headers.get('x-vercel-ip-country');
  return new Response(`Country: ${country}`);
}

A string of up to three characters containing the region-portion of the ISO 3166-2 code for the first level region associated with the requester's public IP address. Some countries have two levels of subdivisions, in which case this is the least specific one. For example, in the United Kingdom this will be a country like "England", not a county like "Devon".

export function GET(request: Request) {
  const region = request.headers.get('x-vercel-ip-country-region');
  return new Response(`Region: ${region}`);
}

The city name for the location of the requester's public IP address. Non-ASCII characters are encoded according to RFC3986.

export function GET(request: Request) {
  const city = request.headers.get('x-vercel-ip-city');
  return new Response(`City: ${city}`);
}

The latitude for the location of the requester's public IP address. For example, 37.7749.

export function GET(request: Request) {
  const latitude = request.headers.get('x-vercel-ip-latitude');
  return new Response(`Latitude: ${latitude}`);
}

The longitude for the location of the requester's public IP address. For example, -122.4194.

export function GET(request: Request) {
  const longitude = request.headers.get('x-vercel-ip-longitude');
  return new Response(`Longitude: ${longitude}`);
}

The name of the time zone for the location of the requester's public IP address in ICANN Time Zone Database name format such as America/Chicago.

export function GET(request: Request) {
  const timezone = request.headers.get('x-vercel-ip-timezone');
  return new Response(`Timezone: ${timezone}`);
}

The signature of the request. This header is used to verify that the request was sent by Vercel, and contains a hash signature you can use to validate the request body.

export function POST(request: Request) {
  const signature = request.headers.get('x-vercel-signature');
  return new Response(`Signature: ${signature}`);
}