---
id: pylzss
version: "0.3.8"
license: LGPL-3.0-only
license_treatment: copyleft
maintenance: dormant
---

# pylzss — A Python library for decoding/encoding LZSS-compressed data.

License: copyleft · Maintenance: dormant · Downloads: 331.9K/mo

## What it is and what it does

pylzss is a Python binding for LZSS compression and decompression. LZSS is a dictionary-based lossless compression algorithm that replaces repeated byte sequences with references to earlier occurrences. The package provides encode and decode functions to work with LZSS-compressed data, making it useful for handling legacy file formats, embedded system data, or any application that needs to read or write LZSS-encoded streams.

The library has no runtime dependencies and is distributed as precompiled wheels for Python 3.8+ across Linux, macOS, and Windows architectures. Maintenance is minimal but stable; the repository is not archived and carries no known security vulnerabilities. The package occupies a narrow niche—it is not a general-purpose compression tool but rather a specialized codec for a specific algorithm.

Use it for:

- Decompress legacy game ROM or firmware data that uses LZSS compression.
- Read or write LZSS-compressed streams in embedded system communication protocols.
- Integrate LZSS codec support into data analysis or forensics tools for proprietary formats.
- Encode data for compatibility with systems or devices that only understand LZSS.
- Migrate or preserve historical data archives that rely on LZSS compression.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

pylzss decodes and encodes data compressed with the LZSS algorithm, a lossless compression method commonly used in legacy data formats and embedded systems.

Yes, if you specifically need LZSS codec support. The package is stable, dependency-free, and carries no known vulnerabilities. Install friction is moderate due to compiled wheels, but prebuilt binaries are available for common platforms. However, this is a narrow-use library; install only if you are working with LZSS-compressed data or legacy formats that require it. For general-purpose compression, use zlib, brotli, or other modern alternatives.

## Install

pip install pylzss
uv add pylzss
poetry add pylzss

## Installing pylzss

Before you install: Medium install friction due to compiled wheels; the package is dormant (last release May 2024, last commit December 2024) with minimal maintenance activity, though it carries no known vulnerabilities and supports Python 3.8 and later across multiple platforms.

License in practice: LGPL-3.0-only is a copyleft license; you may use and modify pylzss freely, but any derivative work must also be licensed under LGPL-3.0 and source code must be made available to users.

Quickstart:

pip install pylzss
import pylzss
compressed_data = b'...'
decompressed = pylzss.decompress(compressed_data)

Requires Python 3.8 or later; precompiled wheels are available for common platforms but source builds may require a C compiler.

Verify before relying:

- Whether the package's LZSS implementation matches a specific variant or standard (e.g., Nintendo LZSS, original algorithm parameters).
- Performance characteristics (speed, memory usage) compared to other LZSS implementations or general-purpose compression libraries.
- Real-world use cases beyond legacy format support—whether active projects depend on this package.

## Package facts

- License: LGPL-3.0-only (copyleft)
- Python support: supports_current
- Install friction: medium
- Maintenance: dormant
- Downloads: 331.9K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

lzss compression library, lzss encode decode, data decompression python, legacy compression format, lossless compression algorithm, compression, codec, legacy-format

[View on SkillFed](https://skillfed.io/packages/pylzss) · [View on PyPI](https://pypi.org/project/pylzss/)