1.6 HTTPS / security / infrastructureHighVerified

Certificate name mismatch

If the certificate does not cover the exact hostname being served, for example www versus the apex, browsers warn that the connection is not trusted. The certificate has to match every hostname in use.

What it is

Cert doesn’t match the served hostname.

Why it matters

Browser warnings; broken secure access.

How to fix it

Issue a cert covering the exact host(s).

How to find it on your site

  1. Visit each hostname variant (apex, www, subdomains) and check for a name-mismatch warning.
  2. Inspect the certificate Subject Alternative Names.
  3. Reissue the certificate to cover all hostnames, or redirect to the covered one.
  4. Re-test every variant.

Cross-reference to ranking and citation factors

A mismatch breaks trust on the affected hostname, which can block crawling and access there. Coverage must match the URLs you actually serve.

Impact

High. Direct.

Evidence

Certificate must match the domain for valid HTTPS. Google Search Central, Secure your site with HTTPS

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