---
title: "Link response headers · Sitebulb Labs"
description: "HTTP Link headers (such as rel=\"alternate\", \"canonical\" or \"describedby\") give agents structured discovery hints."
url: https://labs.sitebulb.com/docs/checks/discoverability/link-headers/
---

# Link response headers

HTTP Link headers (such as rel="alternate", "canonical" or "describedby") give agents structured discovery hints.

- Category

  [Discoverability](https://labs.sitebulb.com/docs/checks/discoverability)

- Standard

  Recommended

## What it checks

The extension requests the site’s root (`/`) and looks for a `Link` response header. When one is present, it lists the `rel` values it found. An agent can read these relationships from the headers alone, without parsing the HTML.

## Results

| Status   | When                                     |
| -------- | ---------------------------------------- |
| **Pass** | The root document sends a `Link` header  |
| **Info** | The root document sends no `Link` header |

This is a bonus check: a `Link` header adds points, and its absence costs nothing.

## How to fix

Add `Link` headers to your responses for the relationships you already express in HTML. For example, pointing to a canonical URL and a Markdown version:

```http
Link: <https://example.com/>; rel="canonical",
      <https://example.com/index.md>; rel="alternate"; type="text/markdown"
```

On Cloudflare Pages or Netlify, a `_headers` file can set this:

```txt
/
  Link: </index.md>; rel="alternate"; type="text/markdown"
```

See also [Markdown alternate link](https://labs.sitebulb.com/docs/checks/content-accessibility/markdown-link-alternate).