How It Works
Every file you process stays on your device. Here is the technology that makes it possible.
The Architecture
1. File Stays in Your Browser
When you select a file, it is loaded into your browser's memory using the File API. The file data is represented as an ArrayBuffer - raw bytes in local RAM. No network request is made.
2. Web Workers Process Your File
Processing happens in a separate thread (Web Worker) so your browser stays responsive. The worker receives the file data via postMessage and processes it entirely in memory.
3. WebAssembly Powers Heavy Lifting
For PDF manipulation, we use pdf-lib.js compiled to efficient bytecode. For background removal, ONNX Runtime Web runs neural networks directly in your browser using WebAssembly.
4. Result Created Locally
The processed result is stored as a Blob URL in your browser's memory. When you click download, the file is saved directly from memory to your disk - no server involved.
Technology Stack
PDF Processing
Pure JavaScript PDF manipulation library that runs entirely in the browser. Handles compression, merging, splitting, and page extraction.
Image Compression
Client-side image compression using Web Workers. Supports JPEG, PNG, and WebP with adjustable quality.
Background Removal
Runs machine learning models (U-Net architecture) directly in your browser using WebAssembly. Same quality as cloud AI services.
HEIC Conversion
WebAssembly port of the libheif library for decoding Apple HEIC/HEIF images without uploading.
File Hashing
Built-in browser API for computing MD5, SHA-256, and SHA-512 hashes. No external libraries needed.
QR Generation
Pure JavaScript QR code generation with customizable colors and sizes. Renders directly to canvas.
Security Measures
File Validation
Triple validation: extension check, MIME type verification, and magic byte analysis to prevent malicious file processing.
Memory Cleanup
All Blob URLs are automatically revoked after 5 minutes. ArrayBuffers are released after processing.
Content Security Policy
Strict CSP headers with nonce-based script loading prevent any unauthorized code execution.
Filename Sanitization
All filenames are sanitized to prevent path traversal, XSS, and other injection attacks.
Network Isolation
Zero external requests during file processing. Verifiable via our Network Inspector or browser DevTools.
No Analytics
No tracking pixels, no analytics scripts, no third-party cookies. Your usage is completely private.