skillfed

blosc

Blosc data compressor

blosc v1.11.4 608.6K downloads/30d#5,779 on PyPI363
Permissive license https://opensource.org/licenses/BSD-3-Clause Active released

What it is and what it does

Blosc is a Python wrapper around the Blosc C library, a high-performance compressor designed to move data to the processor cache faster than uncompressed memory access. It excels at compressing binary data with low entropy—sparse arrays, time series, regularly-spaced grids—and supports multiple compression codecs (blosclz, lz4, lz4hc, zlib, zstd, and optionally snappy). The package provides straightforward Python functions for compression and decompression, with control over compression level, codec selection, and shuffle modes (shuffle and bitshuffle).

The package is production-stable and widely used in scientific and data-processing workflows. It has no runtime Python dependencies and ships with prebuilt wheels for most platforms, though it does require a C compiler if building from source. The maintainers note that Python-Blosc2 is a more modern alternative with additional features, but this package remains actively maintained and suitable for straightforward compression tasks.

Use it for:

  • Compress large numerical arrays in memory before storage or transmission to reduce I/O overhead.
  • Speed up serialization of sparse matrices and time-series data in scientific computing pipelines.
  • Reduce memory footprint of low-entropy datasets in data analysis and machine learning workflows.
  • Accelerate data movement in HPC and distributed computing by compressing between cache and main memory.
  • Archive and transmit gridded or regularly-spaced geospatial or climate data efficiently.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Python wrapper for the Blosc compression library, providing fast compression and decompression of binary data optimized for numerical arrays and low-entropy data.

Yes, if you need fast compression of numerical or binary data. The package is stable, actively maintained, has no Python dependencies, and offers prebuilt wheels for common platforms. However, check whether Python-Blosc2 better suits your needs if you require more advanced features or plan a new project, as the maintainers recommend it as the more modern alternative.

Install

blosc on PyPI

pip

pip install blosc

uv

uv add blosc

poetry

poetry add blosc

Installing blosc

Before you install

Medium install friction due to compiled C extension, but prebuilt wheels are available for common platforms (Windows, macOS, Linux on x86_64 and ARM64). Package is actively maintained with recent releases.

License in practice

BSD-3-Clause permissive license allows commercial and private use with minimal restrictions; attribution required.

Quickstart

pip install blosc

import blosc
compressed = blosc.compress(b'data_to_compress')
decompressed = blosc.decompress(compressed)

Requires Python 3.9 or higher; C extension compilation needed if wheels unavailable for your platform.

Verify before relying

  • Whether the package is still recommended for new projects given the note about Python-Blosc2 being more modern and actively maintained.
  • Performance characteristics and codec availability in the current 1.11.4 release compared to the benchmarked 1.5.1 version shown in documentation.

Package facts

License https://opensource.org/licenses/BSD-3-Clause (permissive)
Python support supports the current Python release (>=3.9)
Install friction medium — platform-specific wheel
Runtime dependencies none
Maintenance actively maintained — 209 days since the last release
Last repo commit
First released
Downloads 608,604/month — #5,779 on PyPI (30-day window, as of 2026-08-14)
Known vulnerabilities none known (OSV.dev, checked 2026-08-14)

Evidence: blosc-1.11.4-cp310-cp310-macosx_10_9_x86_64.whl; blosc-1.11.4-cp310-cp310-macosx_11_0_arm64.whl; blosc-1.11.4-cp310-cp310-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; blosc-1.11.4-cp310-cp310-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; blosc-1.11.4-cp310-cp310-musllinux_1_2_aarch64.whl; blosc-1.11.4-cp310-cp310-musllinux_1_2_x86_64.whl; blosc-1.11.4-cp310-cp310-win32.whl; blosc-1.11.4-cp310-cp310-win_amd64.whl; blosc-1.11.4-cp311-cp311-macosx_10_9_x86_64.whl; blosc-1.11.4-cp311-cp311-macosx_11_0_arm64.whl; blosc-1.11.4-cp311-cp311-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; blosc-1.11.4-cp311-cp311-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl; blosc-1.11.4-cp311-cp311-musllinux_1_2_aarch64.whl; blosc-1.11.4-cp311-cp311-musllinux_1_2_x86_64.whl; blosc-1.11.4-cp311-cp311-win32.whl; blosc-1.11.4-cp311-cp311-win_amd64.whl; blosc-1.11.4-cp312-cp312-macosx_10_13_x86_64.whl; blosc-1.11.4-cp312-cp312-macosx_11_0_arm64.whl; blosc-1.11.4-cp312-cp312-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; blosc-1.11.4-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl

Development Status :: 5 - Production/StableIntended Audience :: DevelopersIntended Audience :: Information TechnologyIntended Audience :: Science/ResearchLicense :: OSI Approved :: BSD LicenseOperating System :: Microsoft :: WindowsOperating System :: UnixProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.9Topic :: Software Development :: Libraries :: Python ModulesTopic :: System :: Archiving :: Compression

Tags

blosc compression pythonfast binary data compressionnumerical array compressionblosc wrapperhigh-performance data compressionsparse data compressiontime series compression
compressionnumerical-datac-extension

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