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SSL Certificate Checker

Generate OpenSSL commands to inspect certificates, decode PEM certificates client-side, and review SSL best practices.

Enter a domain above to generate OpenSSL commands.

What Is an SSL Certificate?

An SSL/TLS certificate binds a cryptographic key to a domain, enabling encrypted HTTPS connections. It contains the issuer, expiry date, Subject Alternative Names (SANs), and the public key used during the TLS handshake.

How This Tool Works

Paste a PEM-encoded certificate and it is decoded entirely in your browser — nothing is sent to a server. You can also enter a domain to generate the exact OpenSSL commands needed to fetch and inspect its certificate chain from the terminal.

Why Check SSL Certificates?

Expired or misconfigured certificates cause browser warnings, break API integrations, and hurt search rankings. Regular checks help you catch expiring certs before they cause downtime.