Technical SEO Audit Real-Time Inspection

Canonical Tag & Indexability Checker

Audit URL canonicalization, inspect <link rel="canonical"> headers, verify self-referencing links, check robots directives, and prevent duplicate content penalties in Google & Bing.

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Canonical Tag Implementation Guide

A canonical tag (<link rel="canonical" href="...">) specifies the master URL for search engines. Using self-referencing canonical tags prevents search engine confusion caused by URL parameters, session IDs, trailing slashes, or HTTP/HTTPS protocol variations.

Read a canonical check as a diagnostic

A canonical tag expresses a preferred URL for duplicate or very similar content. Finding the tag does not establish that Google selected that URL, indexed it, or approved it for advertising. This checker inspects the fetched response; search engines can evaluate other signals.

  1. Test a public URL and inspect its final response status.
  2. Compare the declared canonical with the intended public address.
  3. Check whether redirects, robots directives, and internal links support that address.
  4. Use Search Console URL Inspection when you need Google's reported indexing state.

A blocked fetch, JavaScript-inserted tag, or unusual server response can limit what the checker sees. Investigate the actual response before changing a site-wide template. Keep parameterized pages with distinct content separate when their purpose requires it.

Reference: Google Search Central: canonical URLs.

Guidance revised 22 October 2026.