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HTTP Link Header Builder

Network

Build an HTTP Link response header from URL/rel pairs (preload, preconnect, prefetch, canonical, pagination) with as/type/crossorigin attributes and a plain-English explanation of each entry

The Link response header drives resource hints like preload and preconnect plus pagination and canonical discovery, but hand-writing its comma-separated, semicolon-delimited attribute syntax is easy to get subtly wrong, especially the as attribute preload silently needs to avoid double-fetching a resource. This assembles the header from a list of URL/rel pairs and their as, type, and crossorigin attributes, and flags common mistakes like a preload missing as or more than one canonical link. It builds the header value only. You still add it to your server, CDN, or edge function's response config yourself, and it never fetches or checks that a linked URL actually resolves.

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How to use HTTP Link Header Builder

  • 1.Add one or more link entries with a URL and a rel value like preload, preconnect, canonical, or next/prev.
  • 2.For preload and modulepreload links, set the as attribute (and type for fonts/stylesheets) so the browser applies the correct request priority.
  • 3.Copy the generated Link header snippet into your server, CDN, or edge middleware's response headers.

Frequently asked questions

Does this validate that the URLs exist?
No, it only assembles the header string from what you enter. It never fetches or checks that a linked resource actually resolves.
Why does it warn about a missing as attribute on preload?
Without as, the browser cannot determine the resource's priority or apply the right Content-Security-Policy check, which commonly causes it to fetch the resource twice.
Can I use this instead of a <link> tag in HTML?
Yes, a Link response header has the same effect as the equivalent <link> tag, which is useful when you want to set it from a server or CDN before the HTML is even parsed.
Does it run on a server?
No, this tool runs entirely in your browser. The generated header is yours to add to your own server, CDN, or edge function configuration.

Use via API, SDK, or MCP

cURL# Free: 1,000 req/day · Pro: 10,000 req/day
curl -X POST https://api.utilix.tech/v1/tools/link-header-builder \
  -H "Authorization: Bearer utx_live_..." \
  -H "Content-Type: application/json" \
  -d '{"links":[{"url":"/fonts/inter.woff2","rel":"preload","as":"font","type":"font/woff2","crossorigin":true}]}'

Get an API key from your dashboard · Full API docs →

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