What is PDF Compression?
What is PDF Compression?
PDF compression reduces file sizes by removing redundant data, optimizing images, and applying compression algorithms. This process makes PDFs easier to share via email, faster to upload, and more storage-efficient while maintaining acceptable quality levels. Our tool uses advanced browser-based compression techniques including image resampling, metadata removal, and object stream optimization.
- Reduce file size by 30-70% depending on quality settings
- Quality presets: High (90%), Balanced (70%), Maximum Compression (50%)
- Custom quality slider for precise control
- Remove metadata (author, dates, software info) for additional savings
- Optimize embedded images with canvas-based resampling
- Support for files up to 100MB with 50MB+ warning
- Batch compression with individual progress tracking
- Cancel operations for individual or all files
- 100% Client-side processing: Files never uploaded to server
Why Compress PDFs?
Large PDF files create challenges for email attachments (often limited to 25MB), slow down website loading, consume storage space, and take longer to upload or download. Compressing PDFs solves these issues while preserving readability. Our browser-based tool prioritizes privacy by processing everything locally—no file uploads, no storage, no tracking.
How to Use
- Upload one or multiple PDF files (max 100MB each)
- Choose quality preset: High Quality (90%), Balanced (70%), or Maximum Compression (50%)
- Fine-tune with custom quality slider if needed
- Enable/disable options: Remove metadata, Optimize images
- Note: Higher quality means lower compression ratio
- Click "Compress PDFs" to start processing
- Monitor progress with percentage and animated indicators
- View original → compressed size with reduction percentage
- Download individual files or all as ZIP archive
- Cancel processing anytime for individual or all files
💡 Pro Tips
- Balanced (70%) quality offers best size-to-quality ratio for most documents
- High Quality (90%) recommended for documents with important images or graphics
- Maximum Compression (50%) best for text-heavy PDFs where image quality is less critical
- Files over 50MB may take longer to process—be patient
- Remove metadata to save additional space and improve privacy
- Optimize images for significant size reduction on image-heavy PDFs
PDF Compression Glossary
- PDF Compression
- Process of reducing PDF file size by removing redundancy, optimizing images, and applying compression algorithms without significantly affecting visual quality.
- Quality Ratio
- Percentage (0-100%) determining compression level; higher quality = larger file size but better visual fidelity.
- Object Stream Compression
- PDF optimization technique that compresses internal objects and data structures for reduced file size.
- Metadata Removal
- Deleting document properties (author, dates, software) that add to file size without affecting content.
- Image Resampling
- Reducing image resolution and quality within PDFs to decrease file size; primary source of compression savings.
- Lossy Compression
- Compression method that discards some data (image quality) to achieve smaller file sizes; used in image optimization.
- Lossless Compression
- Compression that preserves all original data while reducing file size through efficient encoding; used for text and metadata.
- Compression Ratio
- Percentage showing file size reduction: (original - compressed) / original × 100. Example: 60% ratio means file is 60% smaller.
- Batch Compression
- Compressing multiple PDF files simultaneously for efficiency; progress tracked individually.
- Web Worker
- Browser technology enabling background processing without blocking UI; required for smooth compression experience.