Entropy Coding Python Packages

glyd

Lossless AI compression: 33% less GPU memory, bit for bit.

constriction

Entropy coders for research and production in Python and Rust.

bigsmall

Lossless AI model compression - ~34% smaller with bit-identical weights; the autopilot profiles your machine, picks the highest fidelity that runs, and streams models bigger than your RAM.

rgclib

Recursive Group Coding (RGC): fast entropy coder with better compression than AC/Huffman on large alphabets – C lib + Python package

lmzip

Fast lossless compression for large model weights: 34% off BF16 checkpoints, byte-for-byte identical, with a CUDA decoder at 111 GB/s

datacortex

World's best JSON/NDJSON compressor. Format-aware lossless compression engine in Rust - schema inference, columnar reorg, type-specific encoding. 2-3x better than zstd on structured data.

py-rans

A lightweight rANSCoder meant for rapid prototyping.

ansnp

Fast python bindings for Asymmetric Numeral Systems (ported from ryg_rans). Supports CompressAI models.

yaecl

YAECL: Yet Another Entropy Coding Library for Neural Compression Research, with Arithmetic Coding and Asymmetric Numeral Systems support