Web Hash Benchmark

Browser benchmark for hashing large user-supplied files. Compares incremental hash algorithms and implementations side by side in dedicated Web Workers with shared streaming logic so timings stay comparable.

Algorithms and implementations

Algorithm	Implementation	Source
SHA-256	hash-wasm	Daninet/hash-wasm
SHA-256	hash-wasm (simd)	@ult/hash-wasm (when WASM SIMD is available)
SHA-256	asmjs	Custom asm.js in hash/sha256/asmjs/
SHA-256	awasm-noble (simd)	@awasm/noble wasm backend (when WASM SIMD is available)
SHA-256	awasm-noble (threads)	@awasm/noble wasm_threads backend (when cross-origin isolated)
SHA-256	crypto.subtle	Browser Web Crypto API (crypto.subtle.digest)
BLAKE3	hash-wasm	Daninet/hash-wasm
BLAKE3	hash-wasm (simd)	@ult/hash-wasm (when WASM SIMD is available)
BLAKE3	awasm-noble (simd)	@awasm/noble wasm backend (when WASM SIMD is available)
BLAKE3	awasm-noble (threads)	@awasm/noble wasm_threads backend (when cross-origin isolated)
BLAKE2b	hash-wasm	Daninet/hash-wasm
BLAKE2b	awasm-noble (simd)	@awasm/noble wasm backend (when WASM SIMD is available)
BLAKE2b	awasm-noble (threads)	@awasm/noble wasm_threads backend (when cross-origin isolated)

The hash-wasm (simd) and awasm-noble (simd) variants are omitted automatically when the browser does not support WebAssembly SIMD. The awasm-noble (threads) variants require cross-origin isolation (Cross-Origin-Opener-Policy: same-origin plus Cross-Origin-Embedder-Policy). The Vite dev server uses credentialless COEP (works with HMR and embedded dev tooling); npm run preview uses stricter require-corp. Both send Cross-Origin-Resource-Policy: cross-origin on served assets. The UI shows badges indicating whether SIMD and WASM threads are available.

The crypto.subtle row uses the typical one-shot pattern (file.arrayBuffer() then crypto.subtle.digest), not incremental streaming. It is omitted when the file exceeds a memory-based size limit (2 GiB when browser memory cannot be detected, or higher when performance.memory / navigator.deviceMemory hints are available). BLAKE3 and BLAKE2b are not available via crypto.subtle.

Each implementation runs in its own long-lived worker. Workers are warmed up before timed runs so JIT and WASM compilation costs are not counted against the benchmark.

Quick start

npm install
npm run dev

Open the URL shown in the terminal (typically http://localhost:5173), drop a file, and click Run benchmark.

OPFS sync access

Enable Use OPFS sync access to copy the file into the Origin Private File System once, then hash it via FileSystemSyncAccessHandle inside the workers with synchronous reads. In this mode you can sweep over multiple chunk sizes (configured in kilobytes).

Leave it off to hash the dropped File directly with async streaming. Chunk size is ignored in this mode because the browser controls how data is read from the stream.

What it measures

For each run the benchmark records:

• Elapsed time (ms)
• Throughput (GB/s)
• Hash digest (hex)

Hashes from every implementation of the same algorithm and iteration are compared. Mismatches are highlighted in the results table. A summary ranks implementations by average throughput.

Scripts

Command	Description
npm run dev	Start Vite dev server
npm run build	Type-check and production build
npm run preview	Preview production build

Project layout

hash/
  sha256/
    asmjs/       # Custom asm.js SHA-256 + worker
    awasm-noble-simd/ # @awasm/noble wasm wrapper + worker
    awasm-noble-threads/ # @awasm/noble wasm_threads wrapper + worker
    wasm/        # hash-wasm wrapper + worker
    wasm-simd/   # @ult/hash-wasm SIMD wrapper + worker
    subtle/      # crypto.subtle.digest wrapper + worker
  blake3/
    awasm-noble-simd/
    awasm-noble-threads/
    wasm/
    wasm-simd/
  blake2/
    awasm-noble-simd/
    awasm-noble-threads/
    wasm/
lib/
  fs.ts          # OPFS read/write helpers
  session.ts     # Long-lived worker session wrapper
  awasm-noble-wasm/ # Tree-shaken @awasm/noble wasm backend glue
  awasm-noble-threads/ # Tree-shaken @awasm/noble wasm_threads backend glue
  awasm-worker.ts # Shared @awasm/noble worker harness
  wasm-worker.ts # Shared hash-wasm worker harness
  types.ts       # Shared types and interfaces
src/
  main.ts        # UI (file drop, controls, results table)
  benchmark.ts   # Benchmark orchestrator
  style.css
index.html