MessagePack to JSON Converter

MessagePack to JSON Converter

Convert between MessagePack binary format and JSON instantly in your browser. Decode MessagePack hex or Base64 strings into readable JSON, or encode JSON data into compact MessagePack format.

How to Use

Decode: Select Decode mode, choose your input format (Hex or Base64), paste your MessagePack data, and get pretty-printed JSON output instantly.

Encode: Select Encode mode, paste valid JSON, choose your output format (Hex or Base64), and get the MessagePack-encoded result.

Features

• Bidirectional Conversion – Convert MessagePack to JSON and JSON to MessagePack in a single tool
• Multiple Input Formats – Accept hex strings and Base64-encoded MessagePack data
• Full Spec Support – Handles all MessagePack types including nil, bool, integers (up to 64-bit), floats, strings, binary, arrays, maps, and extension types
• Size Comparison – See how much smaller MessagePack is compared to the equivalent JSON representation
• Pretty-Printed Output – JSON output is automatically formatted with proper indentation for easy reading
• Client-Side Processing – All conversion happens in your browser with no data sent to any server