zopfli

Zopfli module for python

zopfli Permissive license Apache-2.0 Active ★ 14 v0.4.3 released 2026-06-10

Install

zopfli on PyPI

pip

pip install zopfli

uv

uv add zopfli

poetry

poetry add zopfli

Package facts

License	Apache-2.0 (permissive)
Python support	supports the current Python release (>=3.10)
Install friction	medium — platform-specific wheel
Runtime dependencies	none
Maintenance	actively maintained — 64 days since the last release
Last repo commit	2026-06-10
First released	2013-03-02
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: zopfli-0.4.3-cp310-abi3-macosx_10_9_universal2.whl; zopfli-0.4.3-cp310-abi3-manylinux2014_x86_64.manylinux_2_17_x86_64.whl; zopfli-0.4.3-cp310-abi3-manylinux_2_24_aarch64.manylinux_2_28_aarch64.whl; zopfli-0.4.3-cp310-abi3-musllinux_1_2_aarch64.whl; zopfli-0.4.3-cp310-abi3-musllinux_1_2_x86_64.whl; zopfli-0.4.3-cp310-abi3-win32.whl; zopfli-0.4.3-cp310-abi3-win_amd64.whl; zopfli-0.4.3-cp310-abi3-win_arm64.whl; zopfli-0.4.3-pp311-pypy311_pp73-macosx_10_15_x86_64.whl; zopfli-0.4.3-pp311-pypy311_pp73-manylinux2014_x86_64.manylinux_2_17_x86_64.whl; zopfli-0.4.3-pp311-pypy311_pp73-manylinux_2_24_aarch64.manylinux_2_28_aarch64.whl; zopfli-0.4.3-pp311-pypy311_pp73-win_amd64.whl

Intended Audience :: DevelopersLicense :: OSI Approved :: Apache Software LicenseProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPyTopic :: System :: Archiving :: Compression

About zopfli

from the package's own PyPI description — quoted content, verbatim

|Build Status|

PYZOPFLI

cPython bindings for zopfli <http://googledevelopers.blogspot.com/2013/02/compress-data-more-densely-with-zopfli.html>__.

It requires Python 3.10 or greater.

USAGE

pyzopfli is a straight forward wrapper around zopfli's ZlibCompress method.

from zopfli.zlib import compress
from zlib import decompress
s = 'Hello World'
print decompress(compress(s))

pyzopfli also wraps GzipCompress, but the API point does not try to mimic the gzip module.

from zopfli.gzip import compress 
from StringIO import StringIO
from gzip import GzipFile
print GzipFile(fileobj=StringIO(compress("Hello World!"))).read()

Both zopfli.zlib.compress and zopfli.gzip.compress support the following keyword arguments. All values should be integers; boolean parmaters are treated as expected, 0 and >0 as false and true.

verbose dumps zopfli debugging data to stderr
numiterations Maximum amount of times to rerun forward and backward pass to optimize LZ77 compression cost. Good values: 10, 15 for small files, 5 for files over several MB in size or it will be too slow.
blocksplitting If true, splits the data...

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AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

Zopfli provides Python bindings to Google's Zopfli compression library, enabling denser gzip and zlib compression than standard algorithms at the cost of slower encoding.

Medium friction: precompiled wheels cover CPython 3.10+ and PyPy 3.11 across Linux, macOS, and Windows, but the package requires Python 3.10 minimum. Actively maintained with a recent release (64 days old) and no runtime dependencies.

Apache-2.0 is permissive; you may use, modify, and distribute zopfli freely in commercial and private projects provided you include the license notice.

Usage

pip install zopfli
from zopfli.zlib import compress
from zlib import decompress
compressed = compress(b'Hello World')
original = decompress(compressed)

Requires Python 3.10 or greater.

Verdict: Zopfli is a well-maintained, actively developed compression library with broad platform support and no security vulnerabilities. The Apache-2.0 license is permissive. Install friction is moderate due to the Python 3.10+ requirement and precompiled-wheel dependency, but wheels are widely available. Suitable for projects prioritizing compression ratio over encoding speed.

Needs verification

Whether the compression speed penalty is acceptable for your use case (fact sheet does not quantify performance trade-offs).
Whether the iterative compression parameters (numiterations, blocksplitting) are well-tuned for your data type and size.

zopfli compression pythondense gzip compressionhigh-ratio deflate compressionzlib wrapper pythonbetter compression ratiogoogle zopfli bindingsslow compression high ratio