What Is HTTP Header?
An HTTP header is a key-value pair sent between the browser and server as part of an HTTP request or response. Headers carry metadata like content type, caching instructions, redirect destinations, and security policies.
Why It Matters
HTTP headers control how browsers and servers communicate. For domain forwarding and redirects, specific headers determine:
- Where the redirect goes (Location header)
- Whether browsers cache the redirect (Cache-Control)
- Whether HTTPS is enforced (HSTS)
- How search engines interpret the redirect
Key Headers for Domain Forwarding
Location
The destination URL for a redirect. Present in every 3xx response:
Location: https://new-domain.com/pageCache-Control
Controls whether the browser caches the redirect:
Cache-Control: public, max-age=86400301 redirects are cached by default. 302 redirects are not.
Strict-Transport-Security (HSTS)
Tells browsers to always use HTTPS for this domain:
Strict-Transport-Security: max-age=31536000; includeSubDomainsThis prevents HTTP requests from even reaching the server — the browser upgrades to HTTPS automatically.
Server
Identifies the server software. Domain Forward uses this to identify our redirect servers.
Request vs Response Headers
| Direction | Who Sends | Example Headers |
|---|---|---|
| Request | Browser | Host, User-Agent, Accept, Referer |
| Response | Server | Location, Cache-Control, Content-Type, HSTS |
How Domain Forward Handles This
Domain Forward sends optimized response headers with every redirect:
- Location — your configured destination URL
- Cache-Control — appropriate caching for 301 (cached) or 302 (not cached)
- HSTS — enforces HTTPS on supported domains
- X-Redirect-By — identifies Domain Forward as the redirect handler (useful for debugging)
Related Terms
Related Features
Frequently
asked questions
The Location header specifies the redirect destination. The Cache-Control header controls whether browsers cache the redirect. The Strict-Transport-Security (HSTS) header forces HTTPS. These three are the most important for domain forwarding.
In Chrome, open Developer Tools → Network tab → click a request → Headers section. Or use curl -I https://example.com in a terminal.
Request headers are sent by the browser (Host, User-Agent, Accept). Response headers are sent by the server (Location, Content-Type, Cache-Control). In a redirect, the response headers are what tell the browser where to go.
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