SSL Certificate Checker

Analyze SSL/TLS certificates for any domain to verify security configuration and monitor expiration.

When to Use

• Checking SSL certificate expiration dates
• Verifying certificate chain and issuer
• Troubleshooting HTTPS connection issues
• Auditing website security configuration
• Monitoring certificates before renewal

When NOT to Use

• Penetration testing (this is read-only)
• Internal network certificates (use dedicated tools)
• Certificate installation (this only checks, doesn't install)

Examples

Basic Certificate Check

# Check certificate for a domain
openssl s_client -connect example.com:443 -servername example.com </dev/null 2>/dev/null | openssl x509 -noout -dates -subject -issuer

# Get detailed certificate information
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -text