How It Works

Compression Techniques

Compresso uses advanced compression algorithms to reduce file sizes while maintaining quality.

PDF Compression

We use pdf-lib to analyze and optimize PDF files. The compression process:

  1. Analyzes the PDF structure and identifies optimization opportunities
  2. Reduces image quality where visual loss is minimal
  3. Removes duplicate embedded resources
  4. Optimizes font embedding
  5. Compresses content streams with efficient algorithms

All processing happens in your browser. Your PDF never leaves your device.

Image Compression

We use browser-image-compression and compressorjs for high-quality results:

  1. Reads the image file in your browser
  2. Applies smart compression based on your quality setting
  3. Uses canvas API for real-time preview
  4. Maintains color accuracy and sharpness
  5. Optional format conversion (JPG, PNG, WebP)

The quality slider lets you find the perfect balance between size and quality.

Video Compression

Video files are compressed on our servers using FFmpeg:

  1. Upload your video file securely
  2. Select resolution and quality preset
  3. Server processes video with FFmpeg
  4. Download compressed video
  5. Original and compressed files deleted after 1 hour

Video files are temporarily stored on our servers and automatically deleted after 1 hour.

Compression Levels

Balanced Mode

Reduces file size by ~40% with minimal quality loss. Recommended for most use cases.

Maximum Mode

Reduces file size by ~70% with some quality tradeoffs. Best for large files or strict size limits.

Power User Tips

Keyboard Shortcuts

Navigate faster with keyboard shortcuts (press ? anytime to see this list):

  • Ctrl/Cmd + U → Upload (Home)
  • Ctrl/Cmd + H → History
  • Ctrl/Cmd + B → Batch Compression
  • Ctrl/Cmd + P → PDF Compressor
  • Ctrl/Cmd + I → Image Compressor
  • Ctrl/Cmd + V → Video Compressor

Compression History

All your compressions are automatically saved in your browser's history. View past compressions, see your total savings, and export your history as CSV. Your history never leaves your device.

Share Settings

Click the "Share Settings" button on any compressor page to generate a shareable URL with your current settings. Perfect for team workflows or saving your preferred configurations.

Batch Processing

Process multiple files at once using batch mode. You can mix different file types (PDFs, images, videos) and download all compressed files as a single ZIP archive.

Need to encode or decode files before you compress them?  CodeCipher bundles essential conversion utilities for developers.