fnv1a52

fnv1a52

A fast 52-bit FNV-1a hash implementation for JavaScript

52 bits provides a larger hash space than the classic 32-bit FNV-1a while still fitting entirely inside JavaScript's 53-bit safe integer range (double precision) — so the result is a plain number, no BigInt required. Zero dependencies.

The implementation is based on prior work by @tjwebb (Travis Webb) and @desudesutalk under the MIT license, with extra simplifacations and optimizations (like inline lookup table and faster hex conversion).

If you need full 64 bits hash space, check out @danielroe's https://github.com/danielroe/fnv1a-64

Install

pnpm add fnv1a52
yarn add fnv1a52
npm install fnv1a52

Usage

import { fnv1a52, fnv1a52base36, fnv1a52hex } from 'fnv1a52';

console.log(fnv1a52('hello world'));
//=> 2926792616498590

console.log(fnv1a52hex('hello world'));
//=> 'a65e7023cd59e'

console.log(fnv1a52base36('hello world'));
//=> '0stglysbf6m'

You should NEVER fnv1a52().toString(16)! fnv1a52hex can get you a fixed length zero-padded hex string up to 6x faster via a byte-to-hex lookup table.

The same applies to fnv1a52().toString(36) — always use fnv1a52base36 instead, which can get you a fixed length zero-padded hex string up to 3x faster.

API

fnv1a52(str)

Returns the 52-bit FNV-1a hash of str as a number.

• str: string

fnv1a52hex(str)

Returns the 52-bit FNV-1a hash of str as a lowercase hexadecimal string (fixed length, zero-padded).

• str: string

Prefer this over fnv1a52(str).toString(16) — it uses a byte-to-hex lookup table and is up to 6x faster.

Note the fixed length means this is not always equal to fnv1a52(str).toString(16): a hash below 16 ** 12 keeps its leading zero here, while toString(16) drops it.

fnv1a52base36(str)

Returns the 52-bit FNV-1a hash of str as a lowercase base36 string (fixed length, zero-padded).

• str: string

Prefer this over fnv1a52(str).toString(36) as it is up to 3x faster.

Benchmark

$ pnpm run bench

clk: ~3.15 GHz
cpu: Apple M2 Max
runtime: node 24.18.0 (arm64-darwin)

• fnv1a52 - hex
------------------------------------------------ -------------------------------
fnv1a52 + toString(16)            656.58 ns/iter
fnv1a52hex                        120.82 ns/iter

• fnv1a52 - base36
------------------------------------------------ -------------------------------
fnv1a52 + toString(36) + padStart 506.29 ns/iter
fnv1a52base36                     137.43 ns/iter

License

MIT

---

fnv1a52 Sukka, Released under the MIT License. Authored and maintained by Sukka with help from contributors (list).

Personal Website · Blog · GitHub @SukkaW · Telegram Channel @SukkaChannel · Mastodon @sukka@acg.mn · Twitter @isukkaw · BlueSky @skk.moe