SSL Checker
Analyze any website's SSL/TLS configuration. Check certificate details, protocol support, and known vulnerabilities.
About SSL/TLS Certificates
SSL/TLS certificates are digital credentials that authenticate a website's identity and encrypt data in transit. When you see the padlock icon in your browser, it means the site has a valid certificate and the connection is encrypted using TLS.
This tool uses the Qualys SSL Labs API to perform a deep analysis of any server's SSL/TLS configuration. It checks certificate validity, protocol support (TLS 1.0 through 1.3), cipher suite strength, and known vulnerabilities like Heartbleed, POODLE, and ROBOT.
For best security, aim for an A+ grade by disabling TLS 1.0 and 1.1, using strong cipher suites, enabling HSTS with a long max-age, and ensuring your certificate chain is complete and trusted.
The domain to analyze — SSL Labs connects to the server and performs a full TLS handshake
Negotiate protocol version, cipher suite, and exchange certificates — tests TLS 1.0 through 1.3
Validate the server certificate, intermediate CAs, and root CA — check expiry, signatures, and SANs
Test for known vulnerabilities: Heartbleed, POODLE, BEAST, ROBOT, DROWN, Ticketbleed, and weak ciphers
Overall grade A+ through F based on protocol support, key exchange, cipher strength, and vulnerability exposure
Spec: SSL Labs Grading Criteria, RFC 8446 (TLS 1.3), RFC 5246 (TLS 1.2)