Link header
An HTTP response header, defined in RFC 8288, that carries typed links such as canonical, alternate, describedby or cite-as without touching the page body. It works for files that have no HTML head, like JSON, PDF or CSV.
What Link header does not show
A crawler that reads only the body misses it entirely, so a relation that matters should be stated in both places.
Where Link header comes up on this site
- How an AI agent should verify a website before acting on itEvery Resolve answer carries one in its Link header, pointing at an as-of answer : curl -sI "https://crawlcheck.io/api/v1/resolve?domain=example.com" | grep -i ^link # <…/api/v1/resolve?domain=example.com&as_of=2026-10-09T16:10:04.222Z>; rel="cite-as"…
Terms this definition uses
Definitions that name Link header
Related terms in HTTP, edge and rendering
The delivery layer between an origin and a client: proxies, caches, redirects, status codes and the headers that decide what a crawler actually received.
content negotiation · Markdown negotiation · Retry-After · Server-Timing · WWW-Authenticate · Allow header · Content-Digest · Origin server · Reverse proxy · CDN · Edge node · WAF · Bot score · TLS handshake · DNS resolution · DNS timeout · Connection timeout · Read timeout · Redirect chain · Redirect loop · 301 redirect · 302 redirect · 307 redirect · 308 redirect · 304 response · 404 response · 410 response · 429 response · 500 response · 502 response · 503 response · 504 response · HEAD request · GET request · Content type · MIME sniffing · Content encoding · Compression · Brotli · ETag · Last-Modified · If-None-Match · Cache hit · Cache miss · Cache key · Vary header · Stale response · Stale-while-revalidate · Edge redirect · Origin bypass · Response parity · Header parity · hreflang · canonical URL · HSTS · HSTS preload list · Content-Security-Policy · CSP nonce · edge cache · cache split · cache-buster · Cache-Control · Age header · render-blocking resource · payload text share · lazy loading · 404 and 410 status codes
Questions about Link header
What is Link header?
An HTTP response header, defined in RFC 8288, that carries typed links such as canonical, alternate, describedby or cite-as without touching the page body. It works for files that have no HTML head, like JSON, PDF or CSV.
What does Link header not show or guarantee?
An HTTP response header, defined in RFC 8288, that carries typed links such as canonical, alternate, describedby or cite-as without touching the page body. A crawler that reads only the body misses it entirely, so a relation that matters should be stated in both places.
Which area of the glossary does Link header belong to?
HTTP, edge and rendering: The delivery layer between an origin and a client: proxies, caches, redirects, status codes and the headers that decide what a crawler actually received.
See it in the full glossary · 751 terms across 19 areas.