blake3 to wasm

blake3.wasm is a WebAssembly port of the BLAKE3 cryptographic hash function written in Rust. It enables fast and secure hashing right inside browsers and Node.js.

build

# lets build it!

# For NodeJS
wasm-pack build --target nodejs --release

# For the web!
wasm-pack build --target web --release

SIMD is enabled via wasm32_simd feature in Cargo.toml and requires:

# .cargo/config.toml
[target.wasm32-unknown-unknown]
rustflags = ["-C", "target-feature=+simd128"]

Usage

import * as blake3 from 'blake3-wasm-rs';

const data = new TextEncoder().encode('hello world');
const key = new Uint8Array(32).fill(1);

// One-shot hashing
blake3.hash(data);
blake3.hashXof(data, 64); // variable output length

// MAC and key derivation
blake3.keyedHash(data, key);
blake3.deriveKey('my context', key);

// Conctruct for streaming
const hasher = new blake3.Hasher();

hasher.update(data.slice(0, 5));
hasher.update(data.slice(5));
hasher.finalize();

OR

import { hash, hashXof, keyedHash, deriveKey, Hasher } from 'blake3-wasm-rs'

const data = new TextEncoder().encode('hello world')
const key = new Uint8Array(32).fill(1)

// One-shot hashing
hash(data)
hashXof(data, 64) // variable output length

// MAC and key derivation
keyedHash(data, key)
deriveKey('my context', key)

// Streaming
const h = new Hasher()
h.update(data.slice(0, 5))
h.update(data.slice(5))
h.finalize()

Benchmarks

Tested on Apple M4, Node.js v24.

Size	@noble/hashes	awasm-noble	awasm-noble (threads)	blake3-wasm
32 B	28 MB/s	105 MB/s	94 MB/s	129 MB/s
1 KB	105 MB/s	843 MB/s	819 MB/s	568 MB/s
64 KB	102 MB/s	1,898 MB/s	1,855 MB/s	2,004 MB/s
1 MB	101 MB/s	1,943 MB/s	4,711 MB/s	1,893 MB/s
10 MB	101 MB/s	1,911 MB/s	6,456 MB/s	2,185 MB/s

Tested on Ryzen 7 5800X, Node.js v24.

Size	@noble/hashes	awasm-noble	awasm-noble (threads)	blake3-wasm
32 B	11 MB/s	34 MB/s	45 MB/s	70 MB/s
1 KB	56 MB/s	499 MB/s	526 MB/s	885 MB/s
64 KB	52 MB/s	1,729 MB/s	1,684 MB/s	2,037 MB/s
1 MB	51 MB/s	1,550 MB/s	4,036 MB/s	1,829 MB/s
10 MB	50 MB/s	1,497 MB/s	4,946 MB/s	1,877 MB/s

Security

The underlying blake3 Rust crate targets algorithmic constant time. However, the JavaScript boundary (via napi-rs or WASM) introduces non-determinism from the V8 runtime that is outside our control. For absolute security, use the blake3 Rust crate directly in a Rust program.

See also

• @noble/hashes | pure JS implementation
• awasm-noble | auditable WASM implementation
• blake3-napi | native Node.js addon, faster for large inputs