---
id: deflate
version: "0.8.1"
license: unclear
license_treatment: permissive
maintenance: active
---

# deflate — Python wrapper for libdeflate.

License: permissive · Maintenance: active · Downloads: 331.7K/mo

## What it is and what it does

deflate is a thin Python binding to Eric Biggers' libdeflate C library, exposing compression and decompression for gzip, raw DEFLATE, and zlib formats. It also provides CRC32 and Adler-32 checksum functions. The package is built as a compiled extension with pre-compiled wheels for common platforms, so installation typically requires no build step.

You use it when you need faster compression than Python's built-in zlib module, or when you want to work with raw DEFLATE or zlib data streams where the original decompressed size must be tracked separately. The API is minimal: functions like gzip_compress, deflate_decompress, and crc32 take byte strings and optional parameters (compression level, initial checksum state) and return the result directly.

Use it for:

- Compress large text or binary payloads for network transmission or storage when speed matters more than standard library zlib.
- Decompress gzip or zlib data received from external sources with a simpler API than the standard library.
- Compute rolling CRC32 or Adler-32 checksums across multiple data chunks for integrity verification.
- Work with raw DEFLATE streams where you manage the original size separately, as required by some protocols.
- Replace zlib in performance-critical paths where libdeflate's faster implementation reduces CPU overhead.

## Worth the install?

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

Thin Python wrapper around libdeflate for fast gzip, DEFLATE, and zlib compression/decompression, plus CRC32 and Adler-32 checksum computation.

Yes, if you need faster compression/decompression than the standard library and are comfortable with a compiled dependency. The package is actively maintained, has no known vulnerabilities, and offers pre-compiled wheels for most platforms. Install friction is medium but manageable. Not necessary if standard library zlib meets your performance needs.

## Install

pip install deflate
uv add deflate
poetry add deflate

## Installing deflate

Before you install: Pre-compiled wheels available for common platforms (macOS, Linux, Windows, multiple architectures). Medium install friction due to compiled C extension, but wheels reduce build overhead. Active maintenance with last commit 2026-08-01.

License in practice: MIT license (permissive); you can use this freely in commercial and private projects with minimal restrictions.

Quickstart:

pip install deflate

import deflate
compressed = deflate.gzip_compress(b"hello world!" * 1000, level=6)
original = deflate.gzip_decompress(compressed)

Requires Python 3.9 or later. Pre-compiled wheels available; building from source requires a C compiler and optionally LIBDEFLATE_PREFIX environment variable if linking to system libdeflate.

Verify before relying:

- Performance comparison with standard library zlib or other compression libraries to justify adoption.
- Whether the compression level range (1-12 for libdeflate) offers practical benefits over standard zlib (1-9).
- API stability and backward compatibility guarantees across future releases.

## Package facts

- License: not declared (permissive)
- Python support: supports_current
- Install friction: medium
- Maintenance: active
- Downloads: 331.7K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

gzip compression decompression, deflate compression library, zlib wrapper python, crc32 adler32 checksum, libdeflate python binding, fast data compression, deflate raw compression, compression, c-extension, checksum

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