How It Works
Compress your images in four simple steps. No technical knowledge required.
Upload Your Images
Drag and drop your images into the upload area, or click to browse your files. We support JPEG, PNG, and WebP formats.
- Upload single images or multiple files at once
- Maximum file size depends on your device capabilities
- Files stay in your browser - nothing is uploaded to servers
Adjust Compression Settings
Use the quality slider to find the perfect balance between file size and image quality. Choose your output format.
- Quality ranges from 10% (smallest) to 100% (highest quality)
- Use preset buttons for quick selection (Low, Medium, High, Best)
- Convert between formats (JPEG, PNG, WebP) if needed
Preview and Compare
See the before and after comparison to ensure you're happy with the results. Check file size savings in real-time.
- Interactive slider to compare original and compressed versions
- File size comparison shows exact bytes saved
- Compression ratio displayed as percentage
Download Your Images
Download compressed images individually or as a ZIP file for batch processing. Your compressed files are ready instantly.
- Single images download with "-compressed" suffix
- Batch downloads packaged as a convenient ZIP file
- Original files remain unchanged on your device
Technical Details
Just Compress Images uses your browser's built-in Canvas API for image processing. When you compress an image:
- The image is loaded into memory as a bitmap
- The Canvas API re-encodes it at your specified quality
- The compressed result is created as a new file
- Everything happens in Web Workers to keep the UI responsive
This approach ensures your images never leave your device while still achieving compression results comparable to server-side tools.