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hpack-html-js

v0.1.0

Published

Pure JS HTML compressor for the .hpack format — browser, Chrome extension, Flutter

Vulnerabilities

Powered byPowered by Snyk
  • 0High
  • 0Medium
  • 0Low

Links

Git

Maintainers

andrehrfandrehrf

Keywords

htmlcompressiondeflatehpackcrawlercompressorbrowserchrome-extension

Readme

hpack-html-js

npm License

Pure JavaScript HTML compressor for the .hpack binary format. Designed for browsers, Chrome extensions, Flutter JS bridges, and any JS runtime. Zero WASM dependencies, ~8KB gzipped.

Install

npm install hpack-html-js

Usage

import { pack } from 'hpack-html-js';

const html = '<html>...</html>';

const packed = await pack(html, {
  url: 'https://example.com/page',
  etag: '"abc123"',
  signature: 'req-sig-xyz',
});

// Send packed bytes to server (~80% smaller)
await fetch('/ingest', { method: 'POST', body: packed });

API

pack(html, options)

Compress HTML into a compact .hpack binary packet.

  • html: string — raw HTML to compress
  • options.url: string — source page URL (required)
  • options.etag?: string — HTTP ETag
  • options.signature?: string — request signature for server-side identification
  • options.contentType?: string — original Content-Type
  • options.timestamp?: number — capture time (Unix ms, defaults to Date.now())
  • options.encoding?: string — page encoding (defaults to "utf-8")
  • options.custom?: Record<string, string> — arbitrary key-value metadata
  • options.level?: 'fast' | 'default' | 'max' — compression level (default: "default")
  • options.minify?: boolean — minify HTML before compression (default: true)
  • options.checksum?: boolean — include CRC32 checksum (default: true)
  • Returns Promise<Uint8Array>

minify(html)

Standalone HTML minifier. Removes comments, collapses whitespace, sorts attributes, removes optional closing tags.

  • html: string — raw HTML
  • Returns string — minified HTML

compress(data, level?)

Low-level compression. Uses native CompressionStream when available, falls back to fflate.

  • data: Uint8Array — bytes to compress
  • level?: 'fast' | 'default' | 'max'
  • Returns Promise<{ compressed: Uint8Array, isGzip: boolean }>

Compression Pipeline

Raw HTML (100KB)
  -> Minify (whitespace, comments, attr sorting)  ->  ~85KB
  -> DEFLATE (via fflate or native CompressionStream)  ->  ~21KB
  -> Encode .hpack (magic + headers + body + CRC32)  ->  ~21.2KB

Browser Compatibility

| Environment | Compression Engine | Bundle Cost | |-------------|-------------------|-------------| | Modern browsers (95%+) | Native CompressionStream | 0KB | | Older browsers | fflate fallback | 8KB | | Chrome Extension | fflate (CSP-safe, no WASM) | 8KB | | Flutter JS bridge | fflate | 8KB | | Node.js / Bun / Deno | Native CompressionStream | 0KB |

Decompression

To decompress .hpack packets, use hpack-html (TypeScript) or the hpack-html Rust crate.

Real-World Results

| Page | Raw | Packed | Reduction | |------|-----|--------|-----------| | Americanas.com.br | 101.6 KB | 22.0 KB | 78.4% | | Wikipedia | 489.8 KB | 89.7 KB | 81.7% | | Hacker News | 33.7 KB | 5.8 KB | 82.7% | | Google BR | 176.8 KB | 55.1 KB | 68.8% | | Cloudflare Blog | 105.7 KB | 19.1 KB | 82.0% |

Lossless: unpack(pack(html)) === html verified byte-by-byte on all pages.

License

Apache License 2.0 — See LICENSE for details.