Request

HTTP Host Header

Specifies the domain name of the server and optionally the TCP port number. Mandatory in HTTP/1.1 requests.

Purpose

Allows a single server to host multiple websites (virtual hosting) by telling the server which domain is being requested.

Host: <host>:<port> Example: Host: api.example.com Example: Host: api.example.com:8080

Code Examples

See how to use the Host header in different tools and languages.

curl -H "Host: api.example.com" https://203.0.113.1/resource
# For virtual hosting — send host header to specific IP

Related Headers

Origin

Indicates where the request originates from. Used in CORS to determine if the server allows cross-origin requests.

Referer

Contains the address of the previous page from which the current page was requested. Used for analytics, logging, and cache optimization.

X-Forwarded-For

Identifies the originating IP address of a client connecting through a proxy or load balancer. The standard Forwarded header is preferred in modern applications.

Test Your APIs

API Response Time Checker

Test your APIs and inspect response headers in real-time

HTTP Headers Reference

Complete reference of all HTTP request and response headers

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