About This Tool
Documentation
What does this tool do?
A cryptographic X.509 certificate inspector powered by node-forge. Decodes PEM-encoded certificates (`.pem`, `.crt`, `.cer`) to display Common Name (CN), Organization (O), Issuer Authority, valid date ranges with expiration countdowns, Subject Alternative Names (SANs), public key algorithm and bit length, and SHA-1/SHA-256 fingerprints.
When should you use it?
Use this tool to audit SSL/TLS certificates before server deployment, diagnose certificate expiration warnings, inspect wildcard domain SAN coverage, or verify certificate authority trust chains.
Key Capabilities & Features
Highlights
Parse and decode X.509 SSL/TLS certificates in PEM, CRT, and CER formats
Inspect Subject Common Name (CN), Issuer CA, SAN (Subject Alternative Names), and serial numbers
Validity dates inspection with certificate expiry countdown and validity status alerts
Public key algorithm, key size, and SHA-256 fingerprint verification
Verify SSL certificate chain hierarchy and TLS domain matching