The rel attribute inside link tags (<link>) describes the relation to the resource being linked to. It can take one of these 16 values:

• alternate: Alternate version of the document.
• author: Author of the document.
• dns-prefetch: The DNS lookup and handshake should be prefetched for the linked resource.
• help: A resource for help on about the whole document.
• icon: An icon resource.
• license: License and legal information.
• manifest: Web App Manifest document.
• next: Next document in the series.
• pingback: External resource called for pingbacks in the comments.
• preconnect: The connection should be opened in advance.
• prefetch: The resource should be prefetched.
• preload: The resource should be preloaded.
• prerender: The resource should be prerendered.
• prev: Previous document in the series.
• search: A document meant to perform a search in the current document.
• stylesheet: The most commonly used value. Linking to an external stylesheet.

Note that dns-prefetch, preconnect, prefetch, preload and prerender are simply hints to the browser and are currently experimental. They are not supported in all browsers, and you can refer to the Can I Use? page for more information about browser support. Here’s also a summary about the difference between the different behaviors for these resource hints.

Here’s the typical scenario where we see rel being used:

<link rel='stylesheet' href='style.css' type='text/css'>

See Also

• Rel Attribute for Anchor Tags