---
id: libscrc
version: "1.8.1"
license: unclear
license_treatment: copyleft
maintenance: active
---

# libscrc — Library for calculating CRC3/CRC4/CRC8/CRC16/CRC24/CRC32/CRC64/CRC82

License: copyleft · Maintenance: active · Downloads: 498.9K/mo

## What it is and what it does

libscrc is a Python binding to a compiled CRC calculation library supporting a large range of CRC polynomial variants used in industrial protocols, telecommunications, and data integrity applications. It exposes individual functions for each CRC type (e.g., libscrc.modbus, libscrc.xmodem, libscrc.crc32) that accept byte strings or bytearrays and return integer checksums. The library supports both single-pass calculation and incremental computation, where a previous CRC result can be passed as a second argument to continue checksumming additional data.

The package is distributed as pre-compiled wheels for CPython 2.7 and 3.4–3.12 across Linux (x86_64, ARM, ARM64), macOS, Windows, and musl-based systems, minimizing compilation overhead on common platforms. It has no runtime dependencies beyond the Python standard library and wheel metadata.

Use it for:

- Verify Modbus RTU protocol checksums in industrial automation and SCADA systems
- Calculate CRC16 or CRC32 for data transmission protocols like Xmodem or Zmodem
- Implement incremental CRC checksums for streaming or large file integrity checks
- Validate RFID EPC tags and other embedded system checksums
- Compute TCP/UDP pseudo-header checksums for network packet validation

## Worth the install?

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

libscrc provides a compiled library for calculating CRC checksums across many variants (CRC3 through CRC82), supporting both single-pass and incremental computation on byte data.

Yes, if you need CRC calculation and can accept GPLv3+ licensing. The package is actively maintained, widely pre-compiled, and covers an unusually comprehensive set of CRC variants. Install friction is low for most modern Python environments. Not suitable for proprietary projects without a separate license agreement.

## Install

pip install libscrc
uv add libscrc
poetry add libscrc

## Installing libscrc

Before you install: Medium install friction due to compiled wheels. The package is actively maintained with recent commits and has broad pre-built wheel coverage across Python 2.7 through 3.12 and multiple platforms (x86_64, ARM, Windows), reducing build requirements for most users.

License in practice: Licensed under GPLv3+, a copyleft license. Any derivative work or distribution must also be open-source under compatible terms; proprietary projects cannot use this without obtaining an alternative license.

Quickstart:

pip install libscrc

import libscrc
crc16 = libscrc.modbus(b'1234')
crc16 = libscrc.xmodem(b'5678', crc16)  # incremental

Verify before relying:

- Whether the package is still actively maintained beyond the last release date (2022-08-18) given the 1457 days since release
- Performance characteristics and typical use cases for incremental CRC computation introduced in v1.4+

## Package facts

- License: not declared (copyleft)
- Python support: unspecified
- Install friction: medium
- Maintenance: active
- Downloads: 498.9K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

CRC checksum calculation, cyclic redundancy check library, CRC16 CRC32 CRC8, data integrity verification, modbus CRC checksum, incremental CRC computation, multi-variant CRC algorithms, checksum-validation, protocol-implementation, data-integrity

[View on SkillFed](https://skillfed.io/packages/libscrc) · [View on PyPI](https://pypi.org/project/libscrc/)