TLV Decoder

What Is a TLV Decoder?

A TLV Decoder interprets data formatted in Tag-Length-Value notation. Commonly used in smart-card communications (such as EMV credit cards), network protocols, and IoT devices, TLV structures pack each data element with:

• Tag: Identifier of the data field
• Length: Size of the value in bytes
• Value: Actual data payload

By parsing TLV sequences, a decoder reveals each tag’s meaning and its corresponding value, helping developers debug, audit, or integrate with TLV-based systems.

How to Use Our TLV Parser

• Enter Your TLV Data: In the Input box, paste your TLV-encoded hex string.
• Enable Auto Update: Check the Auto Update box if you want the tool to decode automatically whenever you change the input. Leave it unchecked if you prefer manual decoding.
• Decode the TLV String: Click the Convert button. The tool will parse your hex string into Tag and Value pairs.
• View the Output: The decoded TLV data will be displayed in a table format:
  • Tag column shows each TLV tag.
  • Value column shows the corresponding data. Nested TLV elements are shown indented for clarity.
• Copy the Results: Use the copy icons next to the input or output areas to quickly copy your TLV string or decoded results.

Key Features & Benefits of this Tag Decoder

• Instant TLV Parsing: Decode complex TLV streams in one click, no sign-up required.
• EMV Credit Card Number Decoder: Recognizes standard payment tags (such as PAN and expiration date) for fast EMV analysis.
• Custom Tag Support: Define your own tag dictionary for proprietary protocols.
• Export Options: Download parsed output as JSON or CSV for seamless workflow integration.
• Lightweight & Free: Browser-based, zero setup, and fully free—ideal for developers, QA engineers, and security auditors.

Why Choose Our TLV Decoder?

• Accuracy: Reliable parsing engine used by payment industry professionals
• Speed: Decodes even large TLV messages in under a second
• Privacy: All processing occurs locally in your browser, so your data never leaves your machine
• User-Friendly: Clean UI with copy-to-clipboard and export functionality
• Documentation: Built-in tag reference for common EMV and ISO 7816 fields

Frequently Asked Questions

What is the difference between a TLV Decoder and a hex viewer?

A TLV Decoder understands the Tag-Length-Value format and splits the data into meaningful fields, whereas a hex viewer only displays raw bytes without semantic interpretation.

Can this tool parse credit card data securely?

Yes. Everything runs locally in your browser, so no data is sent to any server. Use it safely for EMV TLV analysis.

What file formats can I export the parsed output as?

You can export as JSON for programmatic use or CSV for spreadsheet analysis.

Does the parser support nested TLV structures?

Absolutely. Our decoder will recursively parse nested TLV and display each level in an indented hierarchy.