X.509 PKI & ASN.1 Certificate Engine

X.509 PEM Certificate & Key Inspector

Dissect and validate X.509 Certificates, Certificate Signing Requests (CSRs), and RSA/ECC Public Keys. Inspect Subject Alternative Names (SANs), trust hierarchy, key length, validity periods, and SHA-256 fingerprints.

X.509 PEM Certificate, CSR & Key Inspector

PKI & ASN.1 Engine

Parse, dissect, and validate .pem, .crt, .csr, and .pub files in-browser. Inspect public keys, SANs, and signatures.

Paste PEM Data (Certificate, CSR, Public Key)

Upload File (.pem, .crt, .csr)

Presets:

Public Key & Curve Audit

Extracts modulus length for RSA (2048/4096-bit) and named curves for ECC (P-256, P-384) while flagging deprecated key sizes.

SANs & Extension Dissector

Decodes Subject Alternative Names, Basic Constraints, Key Usages, and Authority Information Access (AIA) extensions.

Cryptographic Fingerprints

Computes SHA-256, SHA-1, and MD5 fingerprints along with hexadecimal serial numbers for certificate pinning and validation.