Check any website's SSL certificate — expiry date, issuer, TLS version, SANs, and security grade. Free, instant, no signup.
Our SSL checker verifies: certificate validity status, expiry date and days remaining, issuer (Certificate Authority), Subject Alternative Names (SANs), TLS protocol version (TLS 1.2, TLS 1.3), cipher suite, and assigns an overall security grade from A to F.
Expired SSL certificates cause browsers to display security warnings, which drastically increases bounce rate. Google uses HTTPS as a ranking signal — while an expired cert won't directly drop rankings, the user experience impact (users leaving immediately) sends negative engagement signals that hurt rankings indirectly.
TLS 1.3 is the latest Transport Layer Security protocol, offering faster handshakes (reducing page load time) and improved security over older versions. Sites using TLS 1.1 or older are considered insecure by modern browsers. Upgrading to TLS 1.2 or 1.3 improves both security and Core Web Vitals scores.
Check your SSL certificate at least monthly. Set up renewal reminders 60 and 30 days before expiry. Let's Encrypt certificates expire every 90 days and should auto-renew — verify auto-renewal is working. Commercial certificates typically last 1 year. An expired certificate will immediately break your site for all visitors.
Subject Alternative Names (SANs) list all domains and subdomains covered by an SSL certificate. A single certificate can protect multiple domains (e.g., example.com, www.example.com, app.example.com). If your domain isn't listed in the SANs, browsers will show a certificate mismatch error — a critical SEO and UX issue.
Aim for an A grade: valid certificate with 60+ days remaining, TLS 1.2 or 1.3 protocol, strong cipher (256-bit or higher). Grade B means TLS 1.0/1.1 (upgrade needed). Grade C means expiring within 30 days (renew immediately). Grade F means expired or using SSL 2.0/3.0 (critical — fix immediately).