Free SSL Certificate Checker
Enter a domain to inspect its TLS certificate. We'll report the issuer, expiry date, and warn if the certificate is close to expiring.
Why SSL/TLS expiry matters
Once your TLS certificate expires, browsers stop trusting your site — visitors see a full-screen warning and most leave. Search engines also treat expired certs as a major trust signal. Modern certificates (Let's Encrypt and most commercial providers) are short-lived (90 days or less), so monitoring expiry is essential.
What we check
- Certificate validity — whether the host responds on port 443 with a valid certificate chain
- Days until expiry — we warn at 30 days and fail at 7 days
- Issuer — which Certificate Authority issued the certificate
How to fix expiring certificates
Most modern hosts (Vercel, Cloudflare, Netlify, Pantheon) auto-renew TLS certificates for you. If you're managing your own server, run certbot renew on a cron and ensure your reverse proxy reloads after renewal. Set up monitoring (Uptime Kuma, Sentry Uptime, or a calendar reminder 30 days before expiry) so you never get caught out.