mmh3
Python extension for MurmurHash (MurmurHash3), a set of fast and robust hash functions.
Decision gist · record as of 2026-08-14
Yes. mmh3 is actively maintained, widely used (top 1000 PyPI packages), has no known vulnerabilities, and offers a straightforward API for a well-defined task. Install it when you need fast, non-cryptographic hashing for probabilistic data structures, machine learning feature engineering, or IoT security applications. The MIT license and zero runtime dependencies make it a low-friction addition to any project.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.10 or later; compiled wheels available for most platforms but source builds require a C compiler.
- Medium install friction due to compiled wheels; however, prebuilt binaries are available for common platforms (macOS, Linux, Windows) and Python versions 3.10–3.14, making installation straightforward on standard systems.
License · maintenance · safety
permissive license (permissive) — MIT license permits unrestricted use, modification, and distribution with minimal restrictions—suitable for both open-source and commercial projects.
last release 2026-03-05 (162 days) · last repo commit 2026-08-10 · 374 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 73,307,432 downloads/mo, #456 on PyPI
Alternatives
Verify before relying
pip install mmh3
import mmh3
mmh3.hash(b"foo") # returns -156908512 (32-bit signed)
mmh3.hash(b"foo", 42) # with seed 42
mmh3.mmh3_x64_128_digest(b"foo") # returns 16-byte digest- Whether the 128-bit function's buffer protocol optimization (PEP 688) provides measurable speedup for typical workloads.
- Thread safety guarantees for the no-GIL (Python 3.14t) variant beyond the note that it is 'not fully tested yet'.
What it is and what it does
mmh3 wraps MurmurHash3, a family of fast, non-cryptographic hash functions designed by Austin Appleby. It provides multiple function variants returning 32-bit signed/unsigned integers, 64-bit values, or 128-bit digests, all with optional seed parameters. The library has no runtime dependencies and compiles to efficient native code on most platforms.
Typical use cases include probabilistic data structures (Bloom filters, MinHash), feature hashing for machine learning, and favicon hashing for IoT search engines like Shodan. The 128-bit digest function efficiently hashes large buffer objects (numpy arrays, memoryviews, bytearrays) without internal copying, making it suitable for high-performance data processing pipelines.
Use it for
- Implement Bloom filters or other probabilistic data structures for memory-efficient membership testing.
- Calculate favicon hashes for OSINT and cybersecurity reconnaissance using Shodan-compatible hash values.
- Hash large numpy arrays or memoryviews in machine learning pipelines using the 128-bit digest function.
- Use as a seeded hash function for feature hashing in NLP and data mining workflows.
- Build MinHash sketches for approximate similarity detection in large datasets.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
mmh3 is actively maintained, widely used (top 1000 PyPI packages), has no known vulnerabilities, and offers a straightforward API for a well-defined task. Install it when you need fast, non-cryptographic hashing for probabilistic data structures, machine learning feature engineering, or IoT security applications. The MIT license and zero runtime dependencies make it a low-friction addition to any project.
Install
mmh3 on PyPI
Before you install
Medium install friction due to compiled wheels; however, prebuilt binaries are available for common platforms (macOS, Linux, Windows) and Python versions 3.10–3.14, making installation straightforward on standard systems.
Requires Python 3.10 or later; compiled wheels available for most platforms but source builds require a C compiler.
License in practice
MIT license permits unrestricted use, modification, and distribution with minimal restrictions—suitable for both open-source and commercial projects.
Quickstart
pip install mmh3
import mmh3
mmh3.hash(b"foo") # returns -156908512 (32-bit signed)
mmh3.hash(b"foo", 42) # with seed 42
mmh3.mmh3_x64_128_digest(b"foo") # returns 16-byte digestVerify before relying
- Whether the 128-bit function's buffer protocol optimization (PEP 688) provides measurable speedup for typical workloads.
- Thread safety guarantees for the no-GIL (Python 3.14t) variant beyond the note that it is 'not fully tested yet'.
Package facts
| License | permissive license permissive |
| Python support | Supports the current Python release >=3.10 |
| Install friction | Medium. Platform-specific wheel |
| Runtime dependencies | None |
| Maintenance | Actively maintained 162 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 73,307,432 / month, #456 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableIntended Audience :: DevelopersLicense :: OSI Approved :: MIT 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 :: Free Threading :: 2 - BetaTopic :: Software Development :: LibrariesTopic :: Utilities |
Evidence: mmh3-5.2.1-cp310-cp310-macosx_10_9_universal2.whl; mmh3-5.2.1-cp310-cp310-macosx_10_9_x86_64.whl; mmh3-5.2.1-cp310-cp310-macosx_11_0_arm64.whl; mmh3-5.2.1-cp310-cp310-manylinux1_i686.manylinux_2_28_i686.manylinux_2_5_i686.whl; mmh3-5.2.1-cp310-cp310-manylinux1_x86_64.manylinux_2_28_x86_64.manylinux_2_5_x86_64.whl; mmh3-5.2.1-cp310-cp310-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl; mmh3-5.2.1-cp310-cp310-manylinux2014_ppc64le.manylinux_2_17_ppc64le.manylinux_2_28_ppc64le.whl; mmh3-5.2.1-cp310-cp310-manylinux2014_s390x.manylinux_2_17_s390x.manylinux_2_28_s390x.whl; mmh3-5.2.1-cp310-cp310-musllinux_1_2_aarch64.whl; mmh3-5.2.1-cp310-cp310-musllinux_1_2_i686.whl; mmh3-5.2.1-cp310-cp310-musllinux_1_2_ppc64le.whl; mmh3-5.2.1-cp310-cp310-musllinux_1_2_s390x.whl; mmh3-5.2.1-cp310-cp310-musllinux_1_2_x86_64.whl; mmh3-5.2.1-cp310-cp310-win32.whl; mmh3-5.2.1-cp310-cp310-win_amd64.whl; mmh3-5.2.1-cp310-cp310-win_arm64.whl; mmh3-5.2.1-cp311-cp311-macosx_10_9_universal2.whl; mmh3-5.2.1-cp311-cp311-macosx_10_9_x86_64.whl; mmh3-5.2.1-cp311-cp311-macosx_11_0_arm64.whl; mmh3-5.2.1-cp311-cp311-manylinux1_i686.manylinux_2_28_i686.manylinux_2_5_i686.whl
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See also mmhash3 · xxhash · murmurhash2 · bbhash · murmurhash · py-multihash · clickhouse-cityhash · cityhash · pyfarmhash · fnv-hash-fast