⚡ CRC32-V2

use crc32_v2::crc32;

let data = b"Hello, world!";
println!("CRC-32: {:#010X}", crc32(0, data));  // CRC-32: 0xEBE6C6E6
assert_eq!(crc32(0, b"123456789"), 0xCBF43926);

use crc32_v2::byfour::crc32_little_16;

let data: Vec<u8> = (0..1_048_576).map(|i| i as u8).collect();
let crc = crc32_little_16(0, &data);
println!("CRC-32: {crc:#010X}");
assert_eq!(crc32_little_16(0, b"123456789"), 0xCBF43926);

use crc32_v2::byfour::crc32_little_8;

let crc = crc32_little_8(0, b"Hello, world!");
assert_eq!(crc, 0xEBE6_C6E6);

use crc32_v2::byfour::crc32_little;

let crc = crc32_little(0, b"Hello, world!");
assert_eq!(crc, 0xEBE6_C6E6);

use crc32_v2::{crc32, crc32_combine};

let crc1 = crc32(0, b"Hello, ");
let crc2 = crc32(0, b"world!");
let combined = crc32_combine(crc1, crc2, b"world!".len() as u64);
assert_eq!(combined, crc32(0, b"Hello, world!"));

use crc32_v2::Digest;

let mut digest = Digest::new();
digest.update(b"Hello, ");
digest.update(b"world!");
println!("CRC-32: {:#010X}", digest.finalize()); // 0xEBE6C6E6
let bytes: [u8; 4] = digest.digest();            // [0xEB, 0xE6, 0xC6, 0xE6]

[dependencies]
crc32-v2 = { version = "0.2.0", default-features = false }

#![no_std]

use crc32_v2::{crc32, byfour::crc32_little_16, Digest};

let crc = crc32_little_16(0, b"embedded payload");
assert!(crc != 0);

See PYTHON.md for the full API reference.

pip install crc32-rs

from crc32_rs import crc32, crc32_little_16, crc32_bytes, crc32_hex, Digest

print(hex(crc32(b"Hello, world!")))             # 0xebe6c6e6
print(hex(crc32_little_16(b"Hello, world!")))   # 0xebe6c6e6
print(crc32_bytes(b"Hello, world!").hex())      # ebe6c6e6
print(crc32_hex(b"Hello, world!"))              # ebe6c6e6

d = Digest()
d.update(b"Hello, ")
d.update(b"world!")
print(hex(d.finalize()))   # 0xebe6c6e6
print(d.digest().hex())    # ebe6c6e6
print(repr(d))             # Digest(crc=0xEBE6C6E6)

See NODE.md for the full API reference.

npm install crc32-rs

const { crc32, crc32Little16, Digest } = require("crc32-rs");

console.log(crc32(Buffer.from("Hello, world!")).toString(16)); // ebe6c6e6
console.log(crc32Little16(Buffer.from("Hello, world!")).toString(16)); // ebe6c6e6

Measured with cargo bench (lto="fat", opt-level=3, codegen-units=1, overflow-checks=false) on Linux x86-64 (Rust 1.94.1). Full methodology in BENCHMARKS.md.

Key takeaways

• crc32_little_16 achieves ~1,282 MiB/s, the fastest pure-software, safe-Rust CRC-32 path, 3.7× faster than byte-at-a-time.
• For inputs ≤ 1 byte, crc32 (2 ns) wins because slicing variants pay an alignment-prologue cost.
• crc32fast achieves ~11 GiB/s via runtime hardware SIMD. For no_std, embedded, or WASM targets, use crc32-v2.
• Python interpreter overhead dominates for small payloads: Rust is 148× faster for 1-byte inputs.

#![forbid(unsafe_code)] is enforced at the crate root. Every byte of the implementation, 16-table generation, slicing loops, GF(2) matrix arithmetic, and the streaming Digest, is written in safe Rust. The no_std build path carries the same safety guarantees.

• BENCHMARKS.md: Full benchmark methodology and measured results
• RUST.md: Complete Rust API reference with complexity table
• PYTHON.md: Python bindings guide
• NODE.md: Node.js bindings guide
• PACKAGING.md: Debian and RPM packaging guide
• A Painless Guide to CRC Error Detection Algorithms
• zlib: crc32.c: the C source this crate is ported from
• crc32fast: SIMD-accelerated CRC-32 for Rust
• crc: generic CRC for many widths and polynomials

Licensed under the MIT License.