SSL Certificate Checker

Check SSL certificate details, expiry, and covered domains

Domain

Enter a hostname (e.g. example.com). Runs a live TLS scan; the first scan of a new host can take 20-60 seconds.

How it works:This tool runs a live TLS handshake against the domain and reports the certificate actually served: issuer, validity window, covered names, the verified chain, supported TLS protocols, key strength, and forward secrecy, plus an overall security grade. Expiry is calculated from the certificate's Not After date. If a live scan is unavailable, it falls back to the most recently issued certificate from public Certificate Transparency logs (issuance only, not a live handshake).

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What is SSL Certificate Checker?

Free online SSL certificate checker to inspect SSL/TLS certificates for any website.

Check when an SSL certificate expires, see the days remaining until expiry, and confirm whether the certificate is valid right now. View the issuer, subject domain, validity dates, protocol version, and whether the certificate chain is complete. Get warnings for expiring, expired, self-signed, and misconfigured certificates. Useful for monitoring website security and avoiding certificate expiration outages. No signup required.

How to Use SSL Certificate Checker

1Enter a domain name (e.g., example.com)
2Click Check to inspect the SSL certificate
3View certificate details, issuer, and expiration
4Check for warnings about expiring or misconfigured certificates

Frequently Asked Questions

The issuer (Let's Encrypt, DigiCert, etc.), subject (domain name), valid from/to dates, days until expiration, protocol version, and whether the certificate chain is complete.

Check monthly at minimum. Set up monitoring for certificates expiring within 30 days. Let's Encrypt certificates expire every 90 days and should auto-renew, but it's good to verify.

The certificate chain connects your site's certificate to a trusted root certificate authority (CA) through intermediate certificates. A broken chain means browsers won't trust the certificate.

Enter your domain and run the check. The result shows the valid-to date alongside a days-remaining count. If that number is low, renew before it hits zero to avoid browser warnings and downtime for visitors.

Compare the issuer and subject fields. If they are the same and the issuer is not a recognized certificate authority, the certificate is self-signed. Browsers will not trust a self-signed certificate on a public site and will show a security warning.

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