What is a canonical tag?
A canonical tag is a line in a page's HTML that names the preferred URL for that content:
<link rel="canonical" href="https://www.example.com/local-moving">
It matters when the same content can be reached at several addresses, for example over both HTTP and HTTPS, or through a site's sorting and filtering options. Google calls the process of picking one "canonicalization," which it describes as "selecting the representative –canonical– URL of a piece of content."
How does Google choose the canonical URL?
Google groups pages that look the same and picks the one it considers "objectively the most complete and useful for search users." The canonical tag is one input. Google lists the signals in order of strength:
- Redirects: "A strong signal that the target of the redirect should become canonical." See what is a 301 redirect.
- The rel="canonical" tag: "A strong signal that the specified URL should become canonical."
- Sitemap inclusion: a weak signal. See what is an XML sitemap.
Google adds that "indicating a canonical preference is a hint, not a rule." It can still choose another URL.
Why does it matter for a moving company?
Google notes that duplicate URLs "may make it harder for you to track how your content performs in search results," and it may show a version the business didn't intend. Duplicates can appear when a redesign leaves old and new URLs live. Each page should point its canonical tag at its own final URL.