Canonical URL Checker

What Is a Canonical URL?

A canonical URL is declared with <link rel="canonical"> to tell search engines which version of a page is the primary one when duplicates exist (e.g., URL parameters, HTTP/HTTPS, or trailing slashes). This prevents duplicate content issues and focuses ranking signals on the preferred URL.

Why Is It Important for SEO?

Without a canonical tag, search engines may index multiple versions of the same content, splitting link equity and diluting relevance. A correct canonical consolidates those signals so the intended URL is prioritized in search results.

Best Practices for Canonical URLs

• ✔ Add a canonical on every indexable page (self-referencing is fine and recommended).
• ✔ Point to the exact preferred version (HTTPS, domain, path, trailing slash).
• ✔ Use absolute URLs (e.g., https://example.com/page).
• ✔ Keep canonicals consistent with redirects, internal links, and sitemaps.
• ✔ Don’t canonicalize to non-indexable (noindex, blocked) or broken pages.

Quick Example

<link rel="canonical" href="https://example.com/category/product/">

Common Mistakes

• ❌ Canonical points to a different page template (irrelevant target).
• ❌ Canonicalized URL returns 3xx/4xx/5xx instead of 200 OK.
• ❌ Mixing signals (canonical says A, redirects/internal links/sitemap say B).
• ❌ Pointing many unique pages to one canonical when they should be unique.

Canonical URL – FAQ

Is a self-referencing canonical okay?

Yes. It’s best practice on indexable pages and clarifies the preferred URL.

Canonical vs. 301 redirect — which should I use?

Use a 301 redirect when you want users and bots permanently on a single URL. Use a canonical when alternate URLs must remain accessible (e.g., tracking parameters, filters).

Can I canonicalize to a page with noindex or blocked by robots.txt?

No. Canonicals should point to indexable URLs returning 200 OK.

How does canonical interact with hreflang?

Each language/region page should usually self-canonicalize, then point to alternates via hreflang. Don’t canonicalize different languages to one URL.