What is a canonical tag?

Why it exists

The same page can be reachable through several URLs: with and without www, with tracking parameters, with a trailing slash or via filters. Without guidance, search engines choose one themselves, and ranking signals can be split. The canonical tag consolidates them on the version you want.

Example

<link rel="canonical" href="https://www.example.com/services/">

Best practice

• Use one absolute URL, with the correct protocol and host.
• Make each indexable page canonical to itself unless it is a genuine duplicate.
• Point only to pages that return a normal, indexable response, never to a redirect or an error.
• Keep canonical, sitemap and internal links consistent with each other.
• On multilingual sites, combine it with hreflang: each language version canonical to itself, never to another language.

Common mistakes

• Canonicalising every page to the homepage
• Pointing to a URL that is blocked in robots.txt or marked noindex
• Using relative URLs or conflicting tags from a plugin and the theme
• Treating canonical as a command: Google uses it as a strong hint, not an order

How Starboost handles it

Canonical and indexing checks are part of our technical audit. Our free audit covers them.