BrotliCFFI

This library contains Python CFFI bindings for the reference Brotli encoder/decoder, available here_. This allows Python software to use the Brotli compression algorithm directly from Python code.

Install from PyPI:

$ python -m pip install brotlicffi

Install from Conda:

$ conda install -c conda-forge brotlicffi

To use it simply, try this:

import brotlicffi
data = brotlicffi.decompress(compressed_data)

More information can be found in the documentation_.

Using BrotliCFFI in Projects

The API is 100% compatible with the Brotli Python C bindings_. We recommend installing the C bindings on CPython and the CFFI bindings everywhere else (PyPy, etc)

Essentially you use requirements like this:

install_requires=[
    "brotli; platform_python_implementation == 'CPython'",
    "brotlicffi; platform_python_implementation != 'CPython'"
]

and then import the correct Brotli library like so:

try:
    import brotlicffi as brotli
except ImportError:
    import brotli

We provide an example project_ that shows how to use both libraries together to support Brotli with multiple Python implementations.

License

The source code of BrotliCFFI is available under the MIT license. Brotli itself is made available under the Version 2.0 of the Apache Software License. See the LICENSE and libbrotli/LICENSE files for more information.

Authors

BrotliCFFI/brotlipy was authored by Cory Benfield and is currently maintained by Seth Michael Larson.

Changelog

1.2.0.2 (2026-08-21)

• Fixed a bug where Decompressor.decompress() could leave stale

unconsumed input behind after fully consuming a chunk of compressed data, causing subsequent calls to fail or re-process old data.

• Since cibuildwheel dropped support, this release does not include Python 3.8 wheels.

1.2.0.1 (2026-03-05)

• Added support for the free-threaded build of Python 3.14.
• Concurrent sharing of Compressor or Decompressor objects

now raises an exception.

1.2.0.0 (2025-11-21)

• Upgraded libbrotli to v1.2.0.
• Added output_buffer_limit parameter to Decompressor.decompress() and

Decompressor.process() methods to allow mitigation of unexpectedly large output. This addresses potential security concerns where maliciously crafted compressed data could result in excessive memory usage during decompression.

1.1.0.0 (2023-09-14)

• Upgraded libbrotli to v1.1.0
• Added explicit support for Python 3.10, 3.11, and 3.12
• Removed support for Python 2.7, 3.5, and 3.6

1.0.9.2 (2021-04-06)

• Added manylinux_aarch64 wheels

1.0.9.1 (2021-01-27)

• Avoid byte/string comparison warning in error message construction

1.0.9.0 (2021-01-20)

• Updated to v1.0.9 of the Brotli library
• Library version now follows Brotli version
• Removed the dictionary parameter from compress and Compressor
• NOTE: Python 2.7 wheels for Windows likely won't work until

google/brotli#848_ is resolved

0.8.0 (2020-11-30)

• Renamed the package on PyPI to brotlicffi, all further updates will be

published to the new package. Using the brotlipy is deprecated.

• Changed the importable namespace from brotli to brotlicffi to no longer

conflict with the Brotli PyPI package.

• Added process() method to Compressor and Decompressor.
• Added is_finished() method to Decompressor.

0.7.0 (2017-05-30)

• Update to v0.6.0 of the Brotli library.

0.6.0 (2016-09-08)

• Resolved a bug where decompress() would return an empty bytestring

instead of erroring if the provided bytestring was small enough.

• Added the finish() method to the streaming decompressor.

0.5.1 (2016-08-17)

• Update to v0.5.2 of the Brotli library.
• Add new exception type (Error).
• Add compatibility with C++ brotli library by aliasing Error to error.
• Extra error checking of input parameters to the compressor.

0.5.0 (2016-08-16)

• Update to v0.5.0 of the Brotli library.
• Extend one-shot compression API to include all control parameters.
• Added streaming/incremental compression API.
• Added flags to control compression mode.

0.4.0 (2016-08-01)

Update to v0.4.0 of the Brotli library.

0.3.0 (2016-05-11)

Update to v0.3.0 of the Brotli library.

0.2.0 (2015-10-05)

Fix broken brotli.compress support on Windows.

0.1.3 (2015-10-05)

• Added basic for brotli.compress through a C wrapper included in this

library.