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Canonical URL Checker

Check whether the canonical tag is present on your page and which URL it points to

Check Results

This only checks the canonical tag. For a comprehensive analysis, use the full page check.

You can also audit your entire site. Duplicate titles and descriptions, orphan pages, broken links between sections, and other site-wide issues can only be found with a full site audit.

If you don't have an SEO specialist, we can help fix the errors found.

Full Page Check Full Site Audit Fix Errors

What Is Canonical and Why It Matters

The <link rel="canonical"> tag is an HTML element in the <head> section that tells search engines which URL is the preferred (canonical) version of the page. It helps avoid duplicate content issues when the same page is accessible at multiple URLs.

What This Tool Checks

  • Canonical tag presence — whether it exists on the page
  • Count — there should be only one canonical tag per page
  • URL validity — whether the canonical value is a valid absolute URL
  • Self-referencing — whether the canonical points to the current page or a different URL

Why Canonical Matters for SEO

Duplicate content is one of the most common SEO problems. The same page can be accessible with and without www, via HTTP and HTTPS, with sorting parameters or UTM tags. Without a canonical tag, search engines must choose the primary version themselves, and that choice may not favor you.

  • Canonical consolidates link equity on a single URL
  • Prevents ranking dilution across duplicate pages
  • Helps Google properly index your site
  • Resolves duplicates caused by parameters, filters, and pagination

Common Mistakes

  • Missing canonical — the search engine decides which URL to treat as primary
  • Canonical points to a non-existent page (404)
  • Multiple canonical tags — the search engine may ignore all of them
  • Canonical contains a relative URL instead of an absolute one
  • All pages point to the homepage — a serious error that will deindex your pages

Frequently Asked Questions

How is canonical different from a 301 redirect? ▶
A 301 redirect physically sends users and bots to a different URL. Canonical is a hint for search engines: the page remains accessible, but the search engine knows which URL to treat as primary. Canonical is suitable when you need to keep both page versions available to users.
Can canonical point to a different domain? ▶
Yes, cross-domain canonical is allowed. It's used when the same content is published on multiple sites and you want to indicate the original source. However, search engines treat cross-domain canonical as a suggestion, not a directive.
Should canonical match the current page URL? ▶
In most cases, yes — the canonical should point to the page itself (self-referencing canonical). This is a clear signal to search engines that this URL is the primary one. The exception is duplicate pages, which should point to the original.

Other Checks

Indexing Check
robots.txt Check
sitemap.xml Check
SSL Certificate Check
HTTP/HTTPS Check
www Redirect Check
Title Tag Check
Meta Description Check
Headings Check
Canonical Check
Viewport Check
Open Graph Check
Encoding Check
Image Format Check
Alt Tags Check
Lazy Loading Check
Internal Links Check
External Links Check
Broken Links Check
Structured Data Check
Compression Check
HTML Size Check
Render-blocking JS Check
Mixed Content Check
HSTS Check
URL Structure Check