Lepton is a tool and file format for losslessly compressing JPEGs by an average of 22%.

JPEG XL image format reference implementation

Free Lossless Image Format

Free Lossless Audio Codec

JNI binding for Zstd

CD image processing suite with optimized lossless encoders in C#

DFloat11 [NeurIPS '25]: Lossless Compression of LLMs and DiTs for Efficient GPU Inference

Fast In-Memory Data Compression Algorithm (header-only C/C++) 540+MB/s compress, 3000+MB/s decompress, ratio% better than LZ4, Snappy, and Zstd@--1

CharLS, a C++ JPEG-LS library implementation

SimplE Lossless Audio

🧙‍♂️ From developers to developers: a cross-platform tool for losslessly image compression.

Data Compression using Arithmetic Encoding in Python

JavaScript FLAC encoder, decoder

state-of-the-art lossless audio compression

An online .txt file compressor, de-compressor tool which uses Huffman Coding for Lossless data compression.

High-speed lossless data compression of 16 to 512 bytes--get better average compression than QuickLZ for 512-byte blocks. td512 maintains good compression down to 16-byte blocks.

An arithmetic coder for Rust.

A streaming LZ predictor compression tool

Delphi / Free Pascal Compitable JPEG-LS Codec

Java rewrite of Sela lossless audio codec