BER-TLV Parser
Walk a BER-TLV byte stream into a clickable tree, with EMV tag lookup. Handles single-byte and multi-byte tags; short-form and long-form lengths; arbitrary nesting depth. Indefinite-length BER is intentionally not supported (very rare in card / EMV contexts).
Input — BER-TLV bytes
Tree
BER-TLV in one line
BER-TLV (Basic Encoding Rules — Tag, Length, Value) is the encoding the smart-card and EMV worlds use everywhere: SELECT response FCIs, application data, CDOL/PDOL, transaction logs. The tag tells you what the field is, the length tells you how big the value is, and the value is either primitive bytes or another nested TLV stream. This parser handles arbitrary depth and shows EMV-known tags by name.
Spec
ISO/IEC 8825-1 (X.690 BER) and EMV Book 3 (Annex B / Annex C).
Tag dictionary
Built-in EMV tag names — AID, AIP, AFL, ATC, CDOL/PDOL, AC, IPK and more. Add suggestions via contact.