---
id: fnv-hash-fast
version: "2.0.3"
license: MIT
license_treatment: permissive
maintenance: active
---

# fnv-hash-fast — A fast version of fnv1a

License: permissive · Maintenance: active · Downloads: 781.5K/mo

## What it is and what it does

fnv-hash-fast is a Python library that computes FNV-1a 32-bit hashes on byte strings. It attempts to use a compiled C++ implementation for speed when Cython is available, and falls back to a pure Python implementation from the fnvhash package otherwise. The library exports a single primary function, fnv1a_32, which takes bytes as input and returns an integer hash value.

The package targets developers who need fast, non-cryptographic hashing—for example, in hash tables, bloom filters, or data deduplication. It supports Python 3.10 through 3.14 and is distributed as pre-compiled wheels for common platforms (Linux, macOS, Windows) and architectures (x86_64, ARM), reducing installation friction on most systems.

Use it for:

- Hash table or dictionary key generation where speed matters more than cryptographic strength.
- Bloom filter construction for fast membership testing in large datasets.
- Data deduplication or fingerprinting in file systems or caching layers.
- Network packet or message identification in protocols that use FNV hashing.
- Distributed system node selection or consistent hashing without cryptographic requirements.

## Worth the install?

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

Computes FNV-1a 32-bit hashes using a C++ implementation when available, falling back to pure Python via fnvhash.

Yes, if you need a fast FNV-1a implementation and accept that this is a non-cryptographic hash. The package is actively maintained, has no known vulnerabilities, supports modern Python versions, and offers both compiled and pure-Python paths. Install it for performance-sensitive hashing tasks where FNV-1a is already your algorithm of choice; do not use it as a general-purpose cryptographic hash.

## Install

pip install fnv-hash-fast
uv add fnv-hash-fast
poetry add fnv-hash-fast

## Installing fnv-hash-fast

Before you install: Medium install friction due to compiled wheels for multiple platforms and Python versions (3.10–3.14). Active maintenance with a recent release in May 2026 and a commit as of August 2026 suggests ongoing support.

License in practice: MIT license permits unrestricted use, modification, and distribution with minimal restrictions—suitable for commercial and open-source projects alike.

Quickstart:

pip install fnv-hash-fast

import fnv_hash_fast
result = fnv_hash_fast.fnv1a_32(b"hello")
print(result)  # 1335831723

Requires Python 3.10 or later. C++ implementation requires Cython; pure Python fallback from fnvhash is used if unavailable.

Verify before relying:

- Whether the C++ implementation provides measurable performance gains over the pure Python fallback in typical workloads.
- Collision rate or cryptographic properties of the FNV-1a implementation compared to other hash functions.
- Whether this package is suitable for security-critical applications or only for non-cryptographic hashing.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: medium
- Maintenance: active
- Downloads: 781.5K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

fnv hash implementation, fnv1a 32-bit hashing, fast hash function, fnv hash python, hash algorithm library, cryptographic hashing, data fingerprinting, hashing, fnv, performance

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