pure-md5

A lightweight, zero-dependency MD5 hashing library for Node.js and browsers.

Install

npm install pure-md5

Quick Start

import { md5 } from 'pure-md5';

md5('hello'); // "5d41402abc4b2a76b9719d911017c592"

For the smallest possible bundle, import from the minimal entry:

import { md5 } from 'pure-md5/md5'; // ~1.5 KB gzipped

Streaming & File Hashing

import { hashFile, createMD5Stream } from 'pure-md5/stream';

// Hash a file
const result = await hashFile('large-file.bin');
console.log(result.digest); // "abc123..."

// Stream API
import fs from 'fs';
const stream = createMD5Stream();
stream.on('md5', r => console.log('MD5:', r.digest));
fs.createReadStream('large-file.bin').pipe(stream);

Binary Data

import { md5Buffer } from 'pure-md5';

const data = new Uint8Array([0x00, 0xFF, 0x80]);
md5Buffer(data); // correct hash for raw bytes

Features

• Zero dependencies — no external packages, ever
• ~1.5 KB gzipped for md5() (tree-shakeable)
• Streaming — hash multi-GB files without loading into memory
• TypeScript — full type definitions included
• Universal — works in Node.js and browsers
• Binary-safe — correct hashes for non-UTF-8 byte data

API

md5(message: string): string

Compute MD5 hash of a string (UTF-8 encoded).

import { md5 } from 'pure-md5';
md5('hello'); // "5d41402abc4b2a76b9719d911017c592"

md5Buffer(data: Uint8Array | ArrayBuffer): string

Compute MD5 hash of binary data.

import { md5Buffer } from 'pure-md5';
md5Buffer(new Uint8Array([104, 101, 108, 108, 111])); // "5d41402abc4b2a76b9719d911017c592"

md5Async(message: string): Promise<string>

Async wrapper with automatic backend selection.

import { md5Async } from 'pure-md5';
await md5Async('hello'); // "5d41402abc4b2a76b9719d911017c592"

Streaming API (pure-md5/stream)

| Function | Description | |----------|-------------| | hashFile(path, options?) | Hash a file asynchronously with optional progress | | hashFileDigest(path) | Hash a file, return digest only | | hashFileSync(path) | Synchronous file hash (small files) | | verifyFile(path, expected) | Verify file integrity | | createMD5Stream() | Create a Node.js Transform stream | | pipeThroughMD5(source) | Pipe a stream through MD5, get a promise | | fromStream(stream) | Create stream + result promise pair | | createProgressTracker(total, cb) | Progress callback helper |

import { hashFile, createProgressTracker } from 'pure-md5/stream';

const result = await hashFile('video.mp4', {
  onProgress: createProgressTracker(fileSize, pct => console.log(`${pct}%`))
});

WHATWG Streams (Browser)

import { MD5ReadableStream, hashBlob } from 'pure-md5/stream';

// Hash a Blob
const digest = await hashBlob(fileBlob);

// Hash a ReadableStream
const result = await MD5ReadableStream.hash(readableStream);

Backend Adapters

import { NodeCryptoBackend, BrowserBackend, PureJSBackend } from 'pure-md5';

const backend = new NodeCryptoBackend();
await backend.hash('hello');

Use pure-md5/detect for backend detection and fallback utilities.

Comparison

| Feature | pure-md5 | js-md5 | crypto-js | node-md5 | Node crypto | |---------|----------|--------|-----------|----------|-------------| | MD5 only size | ~1.5 KB¹ | ~3 KB | ~68 KB² | ~3 KB | N/A | | Dependencies | 0 | 0 | 0 | 0 | 0 | | Streaming | ✅ | ❌ | ❌ | ❌ | ✅ | | Browser | ✅ | ✅ | ✅ | ❌ | ❌ | | TypeScript | ✅ | ⚠️ | ❌ | ❌ | ❌ | | Binary-safe | ✅ | ✅ | ✅ | ✅ | ✅ | | Tree-shaking | ✅ | ❌ | ❌ | ❌ | N/A |

¹ With import { md5 } from 'pure-md5/md5' ² crypto-js is a monolithic bundle

CDN

<script type="module">
  import { md5 } from 'https://esm.sh/pure-md5';
  console.log(md5('hello'));
</script>

Documentation

• Streaming API
• Streaming Examples
• Migration Guide
• Troubleshooting

Contributing

See Contributing Guide.

git clone https://github.com/eustatos/pure-md5.git
cd pure-md5
npm install
npm test

License

MIT — see LICENSE.md.