Express File Compressor

A flexible, drop-in wrapper over Multer memory storage designed for easy media processing, conversion, and compression on local environments. Handles Images (using sharp), Videos & Audios (using fluent-ffmpeg), Document to PDF conversion (using LibreOffice), PDF optimization, and ZIP generation out of the box.

Features

• 🚀 Drop-in Middleware: Integrates directly into your existing Express/Multer endpoints.
• 🖼️ Image Compression: Auto-converts to WebP/AVIF, resizes, and optimizes images using sharp.
• 📽️ Video & Audio: Compress and transcode videos or audio tracks using fluent-ffmpeg.
• 📄 Doc → PDF Converter: Convert DOCX, PPTX, and XLSX files to PDF on-the-fly via headless LibreOffice.
• 🗜️ PDF Optimizer & Zip Generator: Compress PDFs and pack files into ZIP archives programmatically.

Installation

npm install express-file-compressor

System Requirements (Optional, based on features used)

• Video/Audio processing: Install ffmpeg on your host system and include fluent-ffmpeg in your project.
• Document conversion: Install libreoffice and ensure the soffice command is available in your PATH.

Quick Start (Express Middleware)

const express = require('express');
const flexiMedia = require('express-file-compressor');

const app = express();

// Initialize the media handler middleware
const media = flexiMedia({
  uploadDir: './uploads', // where processed files are stored
  debug: true
});

// Upload single file (automatic conversion to WebP for images)
app.post('/upload', media.single('file'), (req, res) => {
  res.json({
    message: "Upload and processing complete!",
    file: req.file // file.path points to the compressed file
  });
});

// Upload multiple files
app.post('/upload-multiple', media.array('photos', 5), (req, res) => {
  res.json({
    files: req.files
  });
});

Advanced Configuration: Custom Rules

You can fully customize matching criteria, formats, and compression parameters by passing custom rules.

const media = flexiMedia({
  uploadDir: './uploads',
  rules: [
    // 1. Process PNGs to high-quality AVIF
    {
      name: "Convert PNG to AVIF",
      match: (file) => file.mimetype === 'image/png',
      convert: 'image',
      options: { format: 'avif', quality: 80 }
    },
    // 2. Transcode heavy videos to lightweight MP4s
    {
      name: "Compress mp4 video",
      match: (file) => file.mimetype.startsWith('video/'),
      convert: 'video',
      options: { format: 'mp4', videoBitrate: '800k', resolution: '640x?' }
    },
    // 3. Keep original TXT files untouched
    {
      name: "Pass-through text files",
      match: (file) => file.extension === 'txt',
      convert: null // No conversion/compression applied
    }
  ]
});

Direct Programmatic Usage (Without Middleware)

You can also import and use the underlying converters directly inside your application logic.

const { converters } = require('express-file-compressor')();

// 1. Compress Image
const webpBuffer = await converters.compressImage(rawImageBuffer, {
  format: 'webp',
  quality: 80,
  width: 800
});

// 2. Convert Word Document to PDF
const pdfBuffer = await converters.convertDocToPdf(docxBuffer, 'docx');

// 3. Compress files into a ZIP
const zipBuffer = await converters.compressToZip([
  { name: 'document.pdf', buffer: pdfBuffer },
  { name: 'image.webp', buffer: webpBuffer }
]);

License

MIT