HTTP Header

Forwarded

Request

Exposes original client connection information that is altered or lost when a proxy is involved.

HTTP header reference, syntax, examples, and developer usage.

What is the Forwarded header?

The Forwarded HTTP header is used to transmit metadata between a client and server as part of HTTP requests or responses.

HTTP headers define how content should be interpreted, cached, authenticated, secured, or processed by browsers and APIs.

Direction

This is a request header sent by the client to the server.

Syntax

Forwarded: for=<client>; by=<proxy>; host=<host>; proto=<protocol>

Example

Forwarded: for=192.0.2.60; proto=https; by=203.0.113.43; host=example.com

Common use cases

Preserving original client IP through reverse proxies
Forwarding the original protocol (HTTP vs HTTPS) behind a load balancer
Standardized alternative to X-Forwarded-For

Common mistakes

Using the header in the wrong request or response context
Sending invalid header values
Incorrect header syntax
Assuming the header automatically changes server behaviour

Practical developer insight

Forwarded is the RFC 7239 standard replacement for the X-Forwarded-* family of headers. It combines for, by, host, and proto into a single structured header. Despite being the standard, X-Forwarded-For remains more widely used in practice — always validate and sanitize either header before trusting client IP values.