MetaMorpher - Privacy-First File Conversion Platform

Overview

MetaMorpher is a sophisticated, privacy-first file conversion platform that leverages WebAssembly technology to perform unlimited conversions entirely in the browser. Supporting 700+ conversion types across images, videos, audio, and documents, it provides native-like conversion speeds while ensuring complete data privacy through 100% client-side processing.

Problem Statement

Traditional file conversion tools require uploading files to servers, which raises privacy concerns and creates unnecessary delays. Users need a fast, private way to convert media files without compromising their data.

Solution

MetaMorpher brings the power of FFmpeg to the browser through WebAssembly, enabling 100% client-side processing. Combined with specialized libraries for document processing (PDF.js, jsPDF, Mammoth.js), it offers a comprehensive conversion solution. Your files never leave your device, ensuring complete privacy and faster processing. Available as an installable Progressive Web App with full offline support.

Key Features

700+ Conversion Types Supported

Media Formats

• Images (144 conversions): JPG, JPEG, PNG, GIF, BMP, WEBP, ICO, TIF, TIFF, SVG, RAW, TGA
• Videos (256+ conversions): MP4, M4V, MP4V, 3GP, 3G2, AVI, MOV, WMV, MKV, FLV, OGV, WEBM, H264, HEVC
• Audio (49 conversions): MP3, WAV, OGG, AAC, WMA, FLAC, M4A
• Video ↔ GIF: 100+ bidirectional conversions for motion graphics

Document Processing

• Markdown: → PDF, HTML
• HTML: → PDF
• Text: → PDF
• DOCX: → PDF, HTML, Markdown
• PDF: Multi-page extraction to images + automatic ZIP

Advanced Features

Video & Image Operations

• Video Thumbnail Extraction: Extract high-quality frames at 1-second mark
• Multi-Page PDF to Images: Converts all pages with automatic ZIP bundling
• Images to PDF Creator: Drag-to-reorder interface for custom PDF creation
• Scale-Based Rendering: 2x quality rendering for crisp outputs

Progressive Web App (PWA)

• Installable: Desktop and mobile app installation
• Offline Support: Full functionality without internet after first visit
• Auto-Updates: Automatic updates on redeploy with skip-waiting
• Service Worker: Caches app files for lightning-fast loading
• Standalone Mode: No browser UI, like a native app

100% Privacy-Focused

• All conversions happen in your browser using WebAssembly
• Zero file uploads to servers
• No tracking or analytics on file content
• Secure, local processing with HTML sanitization
• Complete data privacy guaranteed

70% Faster Processing

• WebAssembly provides native-like conversion speeds
• No upload/download overhead
• Direct browser processing
• Parallel processing potential

Professional UI/UX

• Drag-and-drop file upload interface with react-dropzone
• Real-time file validation and progress tracking
• Format-specific conversion options
• Toast notifications for feedback
• Dark/Light mode support with next-themes
• Mobile-responsive grid layouts
• Dynamic file type icons
• Human-readable file size display

Tech Stack

Frontend Framework

• Next.js 15 - React framework with optimized builds and App Router
• React 19 - Latest component-based UI library
• TypeScript - Full type safety across entire codebase

Multimedia Processing Engines

• FFmpeg.wasm (v0.12.6) - Core conversion engine for video, audio, and images
  • Loads from CDN (unpkg.com @core 0.12.2)
  • WebAssembly for performance-critical operations
  • Handles 700+ conversion types at native speeds
• PDF.js (v5.4.530) - PDF parsing and rendering
• jsPDF (v3.0.4) - Client-side PDF generation
• Mammoth.js (v1.11.0) - DOCX to HTML/Markdown conversion

Document & File Handling

• markdown-it (v14.1.0) - Markdown parsing and rendering
• html2canvas (v1.4.1) - HTML to image rendering
• DOMPurify (v3.3.1) - HTML sanitization for security
• JSZip (v3.10.1) - ZIP archive creation/extraction for multi-file downloads
• react-dropzone (v14.3.8) - Advanced drag-and-drop file upload

UI Components & Styling

• Tailwind CSS 3 - Utility-first CSS framework with dark mode
• shadcn/ui - Pre-built, customizable UI components
• Radix UI - Accessible component primitives (Dialog, Select, Tabs, Toast)
• lucide-react - Comprehensive icon library (562 icons)
• react-icons - Additional icon sets

Progressive Web App

• next-pwa (v5.6.0) - Service worker and PWA implementation
• next-themes (v0.4.6) - Dark/light mode management

Analytics & Performance

• Vercel Analytics - Performance tracking
• react-ga4 (v2.1.0) - Google Analytics 4 integration

Build Tools

• ESLint - Code quality enforcement with Airbnb config
• Autoprefixer - CSS vendor prefix support
• PostCSS - CSS processing pipeline

Technical Implementation

WebAssembly FFmpeg Integration

File: utils/load-ffmpeg.ts

• Lazy loads FFmpeg.wasm from CDN (unpkg.com)
• Uses toBlobURL for CORS-safe resource loading
• Async initialization before conversion starts
• Command-based operation: ['-i', input, output]
• Specialized 3GP encoding with custom parameters
• Efficient memory management for large files

Conversion Pipeline Architecture

File: utils/convert.ts (216 lines)

Conversion Flow:

1. File type detection via extension
2. Format-specific routing:
   • PDF operations → pdf-converter.ts
   • Document conversions → document-converter.ts
   • Media files → FFmpeg WebAssembly execution
3. Blob creation and URL generation for download

Document Conversion Pipeline

File: utils/document-converter.ts (235 lines)

Supported Conversions:

• Markdown: markdown-it parser → HTML rendering → jsPDF generation
• DOCX: Mammoth.js extraction → HTML processing → PDF/Markdown output
• HTML: DOMPurify sanitization → DOM traversal → Text layout → PDF
• Configurable page sizes (A4, Letter, Legal) and orientations
• Dynamic imports for optimal bundle size

PDF Operations

File: utils/pdf-converter.ts (192 lines)

Features:

• Multi-page detection and handling
• Scale-based rendering (2x for quality)
• Canvas-based page rendering with proper dimensions
• Automatic ZIP creation for multi-page outputs
• Sequential page naming (page-1.jpg, page-2.jpg, etc.)

Archive Handling

File: utils/archive-converter.ts (68 lines)

Capabilities:

• ZIP creation from file arrays using JSZip
• ZIP extraction with filename preservation
• Batch download functionality via zip bundling
• Automatic multi-file packaging

Progressive Web App Implementation

Service Worker Features:

• Auto-generated during build
• Caches app files for offline access
• Full offline functionality after first visit
• Updates on redeploy with skip-waiting
• 192px and 512px app icons

Installation Methods:

• Desktop (Chrome/Edge): Install icon in address bar
• Android: Menu → "Install app"
• iOS: Safari share → "Add to Home Screen"

Performance Optimizations

Code Splitting:

• Dynamic imports for large libraries (jsPDF, markdown-it, mammoth)
• Lazy loading of FFmpeg only when needed
• Route-based code splitting by Next.js
• Efficient blob creation and URL management

UI Responsiveness:

• React hooks for state management (useState, useRef, useEffect)
• Tabs-based interface preventing unnecessary component loading
• Skeleton loading states during FFmpeg initialization
• Real-time progress indication

Build Optimization:

• Next.js automatic code splitting
• Tailwind CSS purging for minimal bundle
• ESLint compliance for maintainability
• Image optimization ready

What I Learned

Building MetaMorpher taught me:

• WebAssembly Integration: Loading and executing FFmpeg.wasm in browser environments
• Client-Side Processing: Handling multimedia conversions without server-side infrastructure
• PWA Development: Service workers, caching strategies, and offline-first architecture
• Document Processing: PDF manipulation, DOCX parsing, and Markdown rendering
• File System APIs: Blob handling, ZIP creation, and multi-file download management
• Performance Optimization: Dynamic imports, lazy loading, and code splitting techniques
• Browser APIs: Canvas rendering, File API, and URL object management
• Component Architecture: Building scalable UI with shadcn/ui and Radix primitives
• Security Best Practices: HTML sanitization with DOMPurify for document conversions
• Type Safety: TypeScript strict mode across complex conversion pipelines

Impact

MetaMorpher provides a completely private and fast way to convert media files without compromising user privacy, while offering enterprise-level features as a free, open-source tool.

Results:

• 700+ Conversions: Comprehensive format support across all media types
• 70% Faster: Processing compared to cloud-based alternatives
• 100% Private: No server uploads, complete client-side processing
• PWA Ready: Installable app with full offline support
• Zero Cost: Free, unlimited conversions with no restrictions
• Production Grade: 48 dependencies expertly integrated
• Type Safe: Full TypeScript coverage across all conversion pipelines
• Global Reach: Deployed on Vercel with CDN distribution

Architecture Highlights

Component Structure:

• app/page.tsx - Main landing page with hero section
• components/dropzone.tsx - 800-line comprehensive file upload interface
• components/images-to-pdf.tsx - Dedicated image-to-PDF creator with drag-to-reorder
• utils/convert.ts (216 lines) - Main conversion routing logic
• utils/document-converter.ts (235 lines) - Document processing pipeline
• utils/pdf-converter.ts (192 lines) - PDF operations and multi-page handling
• utils/archive-converter.ts (68 lines) - ZIP creation and extraction

Technical Metrics:

• 48 production dependencies
• 15+ custom components
• 8 utility modules
• 700+ supported conversions
• Installable PWA on all platforms

Security Features

• HTML Sanitization: DOMPurify for document conversions
• Client-Side Only: No server exposure or data transmission
• Safe File Handling: No automatic execution or dangerous operations
• CSP Compatible: Safe for content security policies
• Privacy First: Zero tracking on file content