snappy

!!! For snappy@6.x and below, please go to node-snappy.

More background about the 6-7 changes, please read this, Thanks @kesla .

🚀 Help me to become a full-time open-source developer by sponsoring me on Github

Fastest Snappy compression library in Node.js, powered by napi-rs and rust-snappy.

For small size data, snappyjs is faster, and it support browser. But it doesn't have async API, which is important for Node.js program.

Install this package

yarn add snappy

Support matrix

Full matrix as text

Node.js

engines.node is >= 10. CI tests Node 22 and Node 24.

Targets

Rust triple	Platform	CI
x86_64-pc-windows-msvc	Windows x64	tested — node 22, 24
aarch64-pc-windows-msvc	Windows arm64	tested — node 22, 24
i686-pc-windows-msvc	Windows x32	built, not tested
x86_64-apple-darwin	macOS x64	tested — node 22, 24
aarch64-apple-darwin	macOS arm64	tested — node 22, 24
x86_64-unknown-linux-gnu	Linux x64 gnu	tested — node 22, 24
x86_64-unknown-linux-musl	Linux x64 musl	tested — node 22, 24
aarch64-unknown-linux-gnu	Linux arm64 gnu	tested — node 22, 24
aarch64-unknown-linux-musl	Linux arm64 musl	tested — node 22, 24
armv7-unknown-linux-gnueabihf	Linux armv7 gnu	tested — node 22 only
s390x-unknown-linux-gnu	Linux s390x	tested — node 22, 24
x86_64-unknown-freebsd	FreeBSD x64	built, not tested
powerpc64le-unknown-linux-gnu	Linux ppc64le	built, not tested
riscv64gc-unknown-linux-gnu	Linux riscv64	built, not tested
aarch64-linux-android	Android arm64	built, not tested
arm-linux-androideabi	Android armv7	built, not tested
aarch64-unknown-linux-ohos	OpenHarmony arm64	built, not tested
wasm32-wasip1-threads	wasm32-wasi, browser	tested — node 24 (NAPI_RS_FORCE_WASI)

Eighteen targets: eleven CI-tested, seven built but not exercised.

Browser

Bundlers resolve the wasm package through the browser export condition. The wasm build allocates shared memory and spawns worker threads, so SharedArrayBuffer must be available — the page has to be cross-origin isolated, served with Cross-Origin-Opener-Policy: same-origin and Cross-Origin-Embedder-Policy: require-corp.

API

One-shot (raw Snappy block format)

export function compressSync(input: Buffer | string | ArrayBuffer | Uint8Array): Buffer
export function compress(input: Buffer | string | ArrayBuffer | Uint8Array): Promise<Buffer>
export function uncompressSync(compressed: Buffer): Buffer
export function uncompress(compressed: Buffer): Promise<Buffer>

Streaming (framed Snappy format)

Streaming uses the Snappy frame format (file extension .sz). This is not the same wire format as the one-shot APIs above — framed output cannot be passed to uncompress(), and raw blocks cannot be passed to the stream decompressors.

Incremental classes

import { Compressor, Decompressor } from 'snappy'

const compressor = new Compressor()
const parts = [compressor.update('Hello '), compressor.update('snappy 🚀'), await compressor.finish()]
const compressed = Buffer.concat(parts)

const decompressor = new Decompressor()
const restored = Buffer.concat([decompressor.update(compressed), await decompressor.finish()])
console.log(restored.toString('utf8')) // Hello snappy 🚀

The valid stream is the concatenation of every update() output plus the finish() tail.

Web Streams

import { compressStream, uncompressStream } from 'snappy'

const restored = uncompressStream(compressStream(source)) // ReadableStream<Uint8Array>

input must be a WHATWG ReadableStream; wrap a Node Readable with Readable.toWeb().

On wasm / browser builds the native transforms are unavailable; a buffered class-API polyfill is used automatically.

Node Duplex factories

import { createReadStream, createWriteStream } from 'node:fs'
import { createCompressStream, createUncompressStream } from 'snappy'

createReadStream('input.txt').pipe(createCompressStream()).pipe(createWriteStream('input.txt.sz'))

Requires a modern Node.js with Web Streams and Duplex.fromWeb (effectively Node 18+).

Performance

Hardware

OS: Windows 11 x86_64
Host: Micro-Star International Co., Ltd. MS-7C35
Kernel: 10.0.22000
Terminal: Windows Terminal
CPU: AMD Ryzen 9 5950X (32) @ 3.400GHz
Memory: 32688MiB

Result

Running "Compress" suite...
Progress: 100%

  snappy:
    4 220 ops/s, ±0.66%   | fastest

  snappy-v6:
    2 018 ops/s, ±0.84%   | 52.18% slower

  gzip:
    233 ops/s, ±0.52%     | slowest, 94.48% slower

  deflate:
    235 ops/s, ±0.45%     | 94.43% slower

  brotli:
    7 ops/s, ±0.51%       | slowest, 99.85% slower

Finished 4 cases!
  Fastest: snappy
  Slowest: brotli

Running "Decompress" suite...
Progress: 100%

  snappy:
    8 528 ops/s, ±1.03%   | fastest

  snappy-v6:
    6 357 ops/s, ±1.76%   | 25.46% slower

  gzip:
    1 406 ops/s, ±1.80%   | slowest, 83.51% slower

  deflate:
    1 435 ops/s, ±1.88%   | 83.17% slower

  brotli:
    1 208 ops/s, ±1.50%   | slowest, 86.99% slower

Finished 4 cases!
  Fastest: snappy
  Slowest: brotli