ASN.1 Viewer

Parses DER-encoded ASN.1 binary data (from PEM certificates or raw hex) and renders it as a human-readable tree — used to inspect X.509 certificates, keys, CRLs, and PKCS objects, all client-side.

• →Paste a PEM-wrapped certificate (-----BEGIN CERTIFICATE-----) or raw DER hex bytes into the input panel.
• →The parser supports SEQUENCE, SET, INTEGER, BIT STRING, OCTET STRING, OID, UTF8String, PrintableString, BOOLEAN, NULL, and context-specific tags.
• →Nested structures (BIT STRING and OCTET STRING containing inner DER) are automatically detected and expanded.
• →Use the Examples picker to load a sample SEQUENCE, RDN set, or full RSA public key certificate for quick testing.