MessagePack

MessagePack is a binary serialization format designed for efficient data interchange. It aims to provide a compact, fast, and language-agnostic representation of common data structures, often described as a binary alternative to JSON. The format emphasizes small message size and low CPU overhead, making it well suited for network communication and storage in resource-constrained environments.

The MessagePack encoding supports a range of data types, including nil, booleans, integers (across various sizes), floating point numbers, strings, binary blobs, arrays, maps (dictionaries), and extension types for user-defined data. It uses a small, fixed set of type markers combined with variable-length length information, enabling compact encoding for typical values. The design concentrates on reducing overhead and allocations, with most implementations offering efficient encode and decode paths. It is not intended to be human-readable, in contrast to text-based formats like JSON.

An extensive ecosystem of implementations exists across programming languages and platforms. This cross-language support makes MessagePack a popular choice for remote procedure calls, messaging systems, and data storage where speed and size matter. Extension types allow custom encodings for time stamps, complex numbers, or domain-specific objects while preserving interoperability. Streaming and incremental parsing are available in many libraries, enabling large or real-time workloads.

Compared with JSON, MessagePack generally yields smaller payloads and faster parsing, at the cost of human readability and ease of debugging. It is widely adopted in microservices, mobile applications, embedded systems, and high-performance data pipelines, where bandwidth or latency constraints are critical.