About SSL Certificate Decoder

What the Tool Does

Paste a PEM certificate or select a .pem, .crt, or .cer file to inspect certificate identity, issuer, validity dates, subject alternative names, serial number, signature algorithm, public key information, extensions, and fingerprints.

Built for Practical Checks

The decoder is useful for developers, system administrators, security teams, and website owners who need a quick certificate details check during deployment, renewal, troubleshooting, or certificate comparison.

Certificate input is processed in the browser and is not uploaded or stored by the decoder workflow. This design keeps routine public certificate inspection simple and helps reduce unnecessary data transfer.

A Clear Scope

This is a certificate inspection utility, not a certificate authority, hosting provider, vulnerability scanner, or replacement for operational security procedures. Always protect private keys and verify important results against trusted records.