Developer ToolsTLV Message Formatter & Parser
Parse, format, and inspect BER-TLV and EMV messages online. Supports multi-byte tags, nested constructed TLV structures, and long-form length encoding.
An advanced developer utility for inspecting Tag-Length-Value (TLV) encoded data structures. Supports complex BER-TLV rules including variable-length tags, recursive constructed elements, and robust validation.
How to Use TLV Message Formatter & Parser
- To Parse: Paste a raw HEX string representing a TLV message into the parser input. The tool will strictly apply BER-TLV rules to parse tags, lengths, and nested constructed elements.
- To Format: After parsing, view the hierarchical tree inspector or copy the Pretty / Compact representations of your structured data.
- To Encode: Edit the hex values directly (in a future version) or verify round-trip integrity by clicking Encode back to HEX.
What Is TLV Message Formatter &?
TLV (Tag-Length-Value) is a fundamental data encoding scheme where each element indicates its type (Tag), its size (Length), and its actual payload (Value). BER-TLV (Basic Encoding Rules) introduces complex capabilities like multi-byte tags, variable-length forms, and constructed (nested) tags used extensively in EMV payment protocols and secure networking.
Primitive EMV Tag
9F0206000000010000
Amount, Authorised: 000000010000
Frequently Asked Questions
What is BER-TLV?
BER-TLV is a standardized set of encoding rules that allows for variable-length structures. Unlike simple TLV, BER-TLV allows tags to span multiple bytes, lengths to use long-form encoding, and tags to be marked as Primitive or Constructed.
Does this parser support multi-byte tags?
Yes. It actively resolves multi-byte tags based on bit 5 of the initial tag byte being set to 0x1F, properly supporting custom EMV application tags.
Can I use this for EMV data?
Yes! EMV strictly relies on BER-TLV encoding. This tool will mathematically parse EMV TLV data payloads accurately into nested structures.
Are my messages processed securely?
Yes. All parsing, validation, and offset calculation occurs entirely locally in your browser. No data is sent to external servers.