A canonical audit after a migration answers one question for every important page: do the redirect, the page itself, the internal links, and the sitemap all identify the same preferred destination? Start from the migration's old-to-new URL map rather than crawling the new site without context. Google recommends preparing that mapping and says each new URL should have a self-referencing canonical annotation. See Google's site-move guidance.

Build the audit sample

Include the home page, major category and service pages, high-traffic articles, campaign landing pages, parameterized or filtered URLs, PDFs or other non-HTML files, and a sample of retired pages. Record the old URL, intended new URL, redirect result, final response code, declared canonical, indexability, sitemap presence, and internal-link source. Expand the sample when a template-level fault appears.

Check each signal

  1. Request the old URL and confirm that a permanent redirect reaches the mapped destination without an avoidable chain.
  2. Request the final URL and confirm a successful response, usable content, and no leftover migration `noindex` rule.
  3. Inspect the final page's canonical. It should normally be absolute, self-referencing, and use the final protocol, host, path, and trailing-slash convention.
  4. Confirm that internal links point directly to the canonical destination instead of relying on redirects.
  5. Confirm that the new XML sitemap lists the intended canonical URL and does not list obsolete or redirected variants.
  6. Check language annotations separately when the site uses regional or language versions.

Google describes redirects and `rel=canonical` annotations as strong canonicalization signals and sitemap inclusion as a weaker signal. It also warns against conflicting signals, such as naming one URL in the sitemap and a different URL in the canonical annotation. See Google's canonical URL documentation.

Resolve exceptions deliberately

Do not force every URL to self-canonicalize. A duplicate print view, tracking variant, or deliberately consolidated page may correctly point elsewhere. Document why the alternate exists and make sure its canonical target is reachable and equivalent enough to represent it. Deleted content that has no relevant replacement should return a genuine 404 or 410 instead of redirecting to an unrelated home page.

Verify over time

Save the first audit as a baseline, then repeat checks after deployment and after search engines have recrawled the move. Review Search Console for selected-canonical mismatches, indexing exclusions, sitemap processing, and traffic on both old and new properties. A migration is not proven complete merely because a browser reaches the new design; the URL-level signals must remain consistent as templates, plugins, and editors change.

Sources

  1. Site Moves and Migrations — Google Search Central
  2. How to Specify a Canonical with rel=canonical and Other Methods — Google Search Central

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