pure-md5

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

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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

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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

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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.

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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

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CDN

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

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Documentation

• Streaming API
• Streaming Examples
• Migration Guide
• Troubleshooting

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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.