Why it matters
The www and non-www versions of a page are exact duplicates that Google clusters, keeping one. Whether a page loads properly counts in canonical selection: a broken certificate, failing JavaScript or a page that cannot load counts against a URL, and Google's slide also listed meta refresh and security.
How to meet it
Pick one origin (for example https://www.example.com), redirect every other combination of protocol and host name with a single 301, serve a valid TLS certificate on every host name that answers, including the redirecting ones, and use only the chosen origin in internal links, canonicals, hreflang and sitemaps. Enable HSTS once HTTPS works everywhere.
How to test it
curl -I on http://example.com, http://www.example.com and https://example.com each returns one 301 to the https://www. URL; a TLS check (openssl s_client or an online scanner) shows a valid certificate on every host name.
How Regensbot covers it
Decided from one URL.
An audit reads the response, the headers, the HTML, robots.txt, the sitemaps and the structured data, and the finding shows the evidence it saw.
Sources
Google documents03
- 01What is canonicalizationGoogle Search Central (opens in a new tab)
- 02How to specify a canonical URL with rel="canonical" and other methodsGoogle Search Central (opens in a new tab)
- 03Redirects and Google SearchGoogle Search Central (opens in a new tab)
Claims in the knowledge base04
- D2-C365ConsistentHandling web duplicationSaid on stage
- D2-C389ConsistentHandling web duplicationShown on screen
- D2-C387ConsistentHandling web duplicationShown on screen
- D2-C396ConsistentHandling web duplicationShown on screen
Claim IDs refer to the Search Central Live 2026 knowledge base. The knowledge base (opens in a new tab)
- Consistent
- Google's documentation supports it without stating it.