1.6 HTTPS / security / infrastructureCriticalVerified
Expired/invalid SSL certificate
An expired or invalid certificate throws a full-page browser warning that stops most users dead. It is also entirely avoidable with auto-renewal, so I treat a lapse as an operational failure.
What it is
Certificate not valid.
Why it matters
Browsers block access with warnings; trust and crawlability suffer.
How to fix it
Renew/fix the certificate; automate renewal.
How to find it on your site
- Check the certificate expiry in the browser, with openssl s_client, or an SSL checker.
- Confirm the certificate chain is complete and trusted.
- Set up automatic renewal so it never lapses.
- Add monitoring that alerts before expiry.
Cross-reference to ranking and citation factors
An invalid certificate blocks access for users and crawlers alike, which is upstream of every ranking and citation signal.
Impact
Severe; access-blocking. Direct.
Evidence
Valid HTTPS is required for the trust/ranking benefit. Google Search Central, Secure your site with HTTPS