xxHash

xxHash is an extremely fast non-cryptographic hash designed by Yann Collet, approaching memory bandwidth limits on modern CPUs, used with LZ4/Zstd compression.

Purpose

Provides RAM-bandwidth-class ultra-fast non-cryptographic hashing for high-performance checksums and sharding.

Mechanism

XXH32/XXH64 maintain 4 accumulators, one round per 16 bytes: acc = acc ⊕ (input × prime); acc = rotl(acc, 13) × prime. Accumulators are merged and avalanched at the end. XXH3 uses AES hardware acceleration for even more speed.

Use cases

Zstd/LZ4 compression verification
Rust xxHash crate
High-frequency hash tables
Game engine internals

Examples

Input
```
hello
```
Output
```
0x391c7cb6
```
XXH32

Common errors

Using xxHash for cryptographic authentication: xxHash is not cryptographic; use HMAC

Related terms

MurmurHash is a non-cryptographic hash designed by Austin Appleby, achieving good distribution and high speed through multiply-and-rotate operations.

FNV (Fowler-Noll-Vo) is a simple non-cryptographic hash that computes quickly via XOR and multiplication by a prime, used for hash tables and fingerprinting.

CRC32 is a 32-bit cyclic redundancy check based on polynomial division over GF(2), used to detect transmission errors — not a cryptographic hash.

BLAKE3 further optimizes BLAKE2 with binary-tree parallelization; far faster than BLAKE2, it also supports XOF and MAC modes.

Related tools

Hash Calculator

Compute MD5, SHA-1, SHA-256, or SHA-512 hashes with hex or Base64 output. Free, private, and 100% client-side.

Hash Crack Speed Reference

Reference table of hash cracking speeds (educational). Free, private, 100% client-side.

Xxhash32 — pure client-side tool. Privacy-first, no server round-trip.

References