🌳 ASN.1 Decoder

Decode ASN.1 DER or PEM into a tree.

ASN.1 data (PEM, or DER/BER as hex or base64)

Reading the tree

Each line shows the byte offset, header and content length, then the type. Context-specific tags appear as [0], [1]…. When a BIT STRING or OCTET STRING contains a complete DER structure (as with public keys and extensions), it is decoded underneath as “encapsulated”. Indefinite-length (BER) encodings are accepted.