fastcrc
A hyper-fast Python module for computing CRC(8, 16, 32, 64) checksum
What it is and what it does
fastcrc is a Python module that wraps Rust-based CRC computation to provide fast checksum calculations for 8, 16, 32, and 64-bit CRC variants. It exposes multiple algorithm implementations (such as cdma2000 for CRC-8, xmodem for CRC-16, aixm for CRC-32, and ecma_182 for CRC-64) as importable functions that accept byte data and return computed checksums. The module has no runtime dependencies and is distributed as pre-compiled wheels for most common platforms.
Typical use cases include data integrity verification, network protocol implementations, and embedded systems communication where CRC checksums are required. The package is actively maintained, supports Python 3.7 and later, and carries permissive MIT licensing.
Use it for:
- Verify data integrity in file transfers or network protocols that mandate specific CRC algorithms.
- Implement embedded systems communication (e.g., industrial protocols, automotive diagnostics) requiring CRC-8, CRC-16, or CRC-32 checksums.
- Compute checksums for firmware or binary payloads in IoT or edge computing applications.
- Validate data in storage systems or databases that use CRC for corruption detection.
- Build incremental checksum validation by chaining CRC computations across data chunks.
Worth the install?
AI-flagged interpretation of the facts on this page — verify before relying
fastcrc computes CRC checksums (8, 16, 32, and 64-bit variants) using multiple algorithm implementations, with a focus on speed through Rust-backed computation.
Yes. fastcrc is actively maintained, carries no security vulnerabilities, has zero runtime dependencies, and offers permissive MIT licensing. Medium install friction is acceptable given pre-built wheels for common platforms. Install it if you need CRC checksums and want compiled-speed performance; skip it if you only need Python's built-in hashlib.crc32 or can tolerate pure-Python performance.
Install
fastcrc on PyPI
pip
pip install fastcrcuv
uv add fastcrcpoetry
poetry add fastcrcInstalling fastcrc
Before you install
Medium install friction due to compiled wheels; however, wheels are pre-built for many platforms (x86_64, aarch64, armv7l, ppc64le, s390x, i686, riscv64, and Windows/macOS variants). Active maintenance with a recent release 100 days ago.
License in practice
Licensed under MIT (permissive), allowing use in commercial and proprietary projects with minimal restrictions.
Quickstart
pip install fastcrc
from fastcrc import crc8, crc16, crc32, crc64
data = b"123456789"
print(crc8.cdma2000(data))
print(crc16.xmodem(data))
print(crc32.aixm(data))
print(crc64.ecma_182(data))
Requires Python 3.7 or later; pre-compiled wheels available for common platforms, but installation on unsupported architectures may require a Rust toolchain.
Verify before relying
- Performance comparison with Python's built-in hashlib.crc32 or other pure-Python CRC libraries to validate 'hyper-fast' claim.
- Which specific CRC algorithms and variants are supported beyond the examples shown (cdma2000, xmodem, aixm, ecma_182).
- Whether incremental/streaming CRC computation is supported (as suggested by the chained xmodem example).
Package facts
| License | not declared (permissive) |
| Python support | supports the current Python release (>=3.7) |
| Install friction | medium — platform-specific wheel |
| Runtime dependencies | none |
| Maintenance | actively maintained — 100 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 949,773/month — #4,659 on PyPI (30-day window, as of 2026-08-14) |
| Known vulnerabilities | none known (OSV.dev, checked 2026-08-14) |
Evidence: fastcrc-0.3.6-cp310-cp310-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; fastcrc-0.3.6-cp310-cp310-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; fastcrc-0.3.6-cp310-cp310-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl; fastcrc-0.3.6-cp310-cp310-manylinux_2_17_s390x.manylinux2014_s390x.whl; fastcrc-0.3.6-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl; fastcrc-0.3.6-cp310-cp310-manylinux_2_31_riscv64.whl; fastcrc-0.3.6-cp310-cp310-manylinux_2_5_i686.manylinux1_i686.whl; fastcrc-0.3.6-cp310-cp310-musllinux_1_2_aarch64.whl; fastcrc-0.3.6-cp310-cp310-musllinux_1_2_armv7l.whl; fastcrc-0.3.6-cp310-cp310-musllinux_1_2_i686.whl; fastcrc-0.3.6-cp310-cp310-musllinux_1_2_x86_64.whl; fastcrc-0.3.6-cp310-cp310-win_amd64.whl; fastcrc-0.3.6-cp311-cp311-macosx_10_12_x86_64.whl; fastcrc-0.3.6-cp311-cp311-macosx_11_0_arm64.whl; fastcrc-0.3.6-cp311-cp311-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; fastcrc-0.3.6-cp311-cp311-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; fastcrc-0.3.6-cp311-cp311-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl; fastcrc-0.3.6-cp311-cp311-manylinux_2_17_s390x.manylinux2014_s390x.whl; fastcrc-0.3.6-cp311-cp311-manylinux_2_17_x86_64.manylinux2014_x86_64.whl; fastcrc-0.3.6-cp311-cp311-manylinux_2_31_riscv64.whl
Keywords: crc, crc8, crc16, crc32, crc64
Tags
More Python Modules packages
Converts domain names between Unicode and…
permissive · top 100 on PyPI
setuptoolsSetuptools is a Python build backend and…
permissive · top 100 on PyPI
PyYAMLPyYAML parses and emits YAML 1.1 data format,…
permissive · top 100 on PyPI
pydanticPydantic validates Python data structures…
permissive · top 100 on PyPI
annotated-typesProvides reusable metadata objects for use with…
permissive · top 100 on PyPI
typing-inspectionProvides runtime tools to inspect and…
permissive · top 100 on PyPI
crcCalculate, verify, and manage CRC checksums…
permissive · top 5,000 on PyPI
crcmodComputes Cyclic Redundancy Check (CRC) values…
permissive · top 5,000 on PyPI
libscrclibscrc provides a compiled library for…
copyleft · top 15,000 on PyPI
anycrcCalculates CRC hashes of arbitrary bit widths…
permissive · top 15,000 on PyPI
crccheckCalculates CRC and checksum values from binary…
permissive · top 5,000 on PyPI
crc32cComputes CRC32C checksums using hardware…
copyleft · top 1,000 on PyPI
crcengineCrcEngine provides table-based and bit-bashing…
copyleft · top 15,000 on PyPI
filehashCalculates and verifies file checksums and…
permissive · top 15,000 on PyPI
google-crc32cProvides a fast CRC32C checksum computation by…
unclear · top 1,000 on PyPI