HTTP Header

Link

Response

Associates the current resource with related resources or metadata.

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

What is the Link header?

The Link 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 response header sent by the server to the client.

Syntax

Link: <uri>; rel="<relation-type>"[; as="<type>"][; crossorigin]

Example

Link: </styles.css>; rel="preload"; as="style"

Common use cases

Preloading critical assets before the HTML parser discovers them
Prefetching future resources or providing DNS prefetch hints
Declaring canonical URLs and alternate resource relationships for SEO
Pagination links in REST APIs using rel=next and rel=prev

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

The HTTP Link header is functionally equivalent to the HTML <link> tag but can be sent before the HTML is parsed — making it especially effective as an Early Hints (103) response for fonts and render-blocking CSS. In REST APIs, it is widely used for pagination following RFC 8288.