xxHash is an extremely fast non-cryptographic hash algorithm that processes data at RAM speed limits. The library provides three main algorithms: XXH32 for 32-bit hashes, XXH64 for 64-bit hashes, and XXH3 for 64 or 128-bit hashes using vectorized arithmetic. All variants pass the SMHasher test suite, which evaluates collision, dispersion, and randomness properties.
The tool solves the problem of needing high-speed hashing for applications where cryptographic security is not required. It achieves its performance by using highly optimized code that operates at memory bandwidth limits and by employing vectorized arithmetic in XXH3. The implementation is portable across platforms and produces identical hashes regardless of endianness, making it suitable for cross-platform consistency.
Developers should choose xxHash when building systems that require fast hashing for non-security purposes, such as hash tables, bloom filters, checksums, or data deduplication. It excels at both large data processing and small data scenarios, with XXH3 specifically designed to maintain strong performance across input sizes. The tool is particularly valuable when hashing small amounts of data frequently, where initialization and finalization overhead typically becomes a bottleneck in other algorithms.
The project maintains active continuous integration across both release and development branches. The codebase includes comprehensive test suites beyond standard benchmarking, with additional tests specifically evaluating speed and collision properties of 64-bit hashes. The tool is written in C with a focus on portability and has a documented reference implementation available for benchmarking purposes.
