SSL Certificate Checker β Validity, Expiry & Trust
An SSL/TLS certificate encrypts traffic between browsers and web servers. Expired or misconfigured SSL certificates cause browser warnings, loss of user trust, and SEO ranking drops. Check any domain's certificate in seconds.
Why is my SSL certificate showing as invalid?
Common reasons: certificate expired, domain name mismatch (www vs non-www), self-signed certificate, untrusted Certificate Authority, or intermediate certificate missing from the chain.
How often do SSL certificates expire?
Standard TLS certificates (Let's Encrypt, DigiCert, etc.) expire every 90 days to 1 year. Let's Encrypt issues 90-day certificates that should auto-renew via certbot.
What is a SAN (Subject Alternative Name)?
SAN allows one certificate to cover multiple domains (e.g. example.com and www.example.com and api.example.com). Modern certificates always use SANs.
Does SSL affect SEO?
Yes. Google confirmed HTTPS as a ranking signal since 2014. An invalid or expired SSL certificate can cause your site to be flagged as insecure and drop in rankings.