# cespare/xxhash

A Go implementation of the 64-bit xxHash algorithm (XXH64)

Repository: https://github.com/cespare/xxhash
Canonical: https://ross.abutalabs.com/products/cespare-xxhash
Language: Go
License: MIT
License Family: permissive
Last push: 2024-07-03T18:24:03+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3658, "days_push": 791, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2140, forks 139 (observed 2026-08-28T04:06:18.270014+00:00)

## What it is
A Go implementation of the 64-bit xxHash (XXH64) algorithm with a simple API including a hash.Hash64-compatible Digest type. It offers optimized pure Go code plus faster assembly implementations for amd64 and arm64.

## Use cases
- fast non-cryptographic hashing in Go
- hash table key hashing for caches
- checksumming data quickly
- implementing hash maps or bloom filters
- replacing slow standard library hashing

## When to choose
- you need a very fast 64-bit non-cryptographic hash in Go
- you want hash.Hash64 compatibility
- you need proven production use (used by Prometheus, InfluxDB, Badger)

## When to avoid
- you need cryptographic security (use SHA-256 or similar)
- you need XXH3 or 32-bit variants
- you are not working in Go

## Facets
- artifact type: library
- maturity: stable
- function: caching, developer-tools
- domain: developer-tools, databases, performance
- platform: go, windows, cross-platform
- tags: hashing, xxhash, xxh64, checksum, assembly-optimized, linux, macos

## Member repositories
- cespare/xxhash (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:18.270014+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:51:28.210615+00:00, confidence not recorded.
  - readme: https://github.com/cespare/xxhash (fetched 2026-08-28T04:06:18.270014+00:00, sha f744c6198eb2)
- Data as of 2026-08-30T08:39:29.467469+00:00.