MessagePack Pro Converter

Convert between JSON and MessagePack binary format. Supports timestamps, binary data, and extension types.

About MessagePack

MessagePack is an efficient binary serialization format that's smaller and faster than JSON. It's used in applications where bandwidth and storage efficiency matter, like IoT, gaming, and real-time systems.

Compact Size

Binary format uses fewer bytes than text-based JSON. Numbers and small strings are especially efficient.

Extension Types

Supports custom types like timestamps (-1), preserving type information that JSON loses.

Binary Data

Native binary support without Base64 encoding. Perfect for images, files, and raw bytes.

Cross-Platform

Libraries available for 50+ languages including JavaScript, Python, Go, Rust, and more.

Fast Parsing

Binary format can be parsed without tokenization, making it faster than JSON parsing.

Type Preservation

Distinguishes between integers and floats, maps and arrays. No type ambiguity.

MessagePack Type Reference

Type Format Range / Notes
positive fixint0xxxxxxx0 to 127
negative fixint111xxxxx-32 to -1
fixstr101xxxxx0-31 bytes
fixarray1001xxxx0-15 elements
fixmap1000xxxx0-15 pairs
ext (timestamp)type = -1Nanosecond precision