Canonical URL

A canonical URL tells search engines which version of similar content should be treated as the main page.

Canonical tags are hints, not absolute commands. They work best when internal links, redirects, sitemaps, and page content all support the same preferred URL.

When canonical URLs matter

Canonical signals are most useful when the same or very similar content is available through multiple URLs. Common examples include tracking parameters, filtered category pages, HTTP and HTTPS variants, slash and non-slash versions, and duplicated content across templates.

The goal is to make the preferred URL obvious. If the canonical tag says one thing but internal links, redirects, and sitemap entries say another, search engines may choose a different URL.

Checks to run

• Confirm every indexable page points to a canonical URL that returns 200.
• Make sure canonical URLs are absolute, clean, and not blocked by robots rules.
• Check that internal links point to the same preferred version.
• Remove non-canonical URLs from XML sitemaps when possible.
• Watch for canonical tags that point to unrelated or redirected pages.

Common mistakes

Do not use canonical tags as a substitute for cleanup when pages should be redirected, noindexed, merged, or removed.

Canonicalization is strongest when it supports a clear content decision: which page should rank, which page should consolidate signals, and which duplicate versions should fade from search.