PDF Compressor

About PDF Compressor

Our PDF Compressor helps you reduce PDF file sizes while maintaining document quality. Perfect for email attachments, web uploads, cloud storage, and sharing large documents.

Compression Levels

• Low Compression: Minimal size reduction, maximum quality preservation. Best for PDFs with high-quality images, graphics, or photos.
• Medium Compression: Balanced approach with good quality and reasonable file size reduction. Recommended for most documents.
• High Compression: Maximum size reduction. Best for text-heavy documents or when file size is the primary concern.

Common Use Cases

• Email Attachments: Reduce file size to meet email size limits (typically 25MB)
• Web Uploads: Faster uploads and downloads for web forms and applications
• Cloud Storage: Save storage space in Google Drive, Dropbox, OneDrive
• Mobile Sharing: Easier to share on mobile devices with limited bandwidth
• Archiving: Reduce storage requirements for document archives
• Website Performance: Faster page loads for downloadable PDFs

How PDF Compression Works

PDF compression reduces file size through several techniques:

• Image Optimization: Reduces image resolution and quality while maintaining readability
• Font Subsetting: Includes only used characters from embedded fonts
• Object Removal: Removes duplicate or unused objects
• Stream Compression: Applies efficient compression algorithms to content streams
• Metadata Cleanup: Removes unnecessary metadata and comments

Expected Compression Ratios

This tool uses client-side PDF optimization which typically achieves:

• Structure optimization: 5-20% size reduction
• Metadata removal: 1-5% additional reduction
• Object stream compression: Varies by PDF complexity
• Best results: PDFs with redundant objects or metadata

Note: Significant compression (50-80%) of image-heavy PDFs requires server-side image compression tools like Ghostscript or commercial APIs.

Tips for Best Results

• Start with medium compression and adjust if needed
• Preview compressed PDFs before sharing
• Use low compression for professional presentations
• High compression works well for internal documents
• Consider your audience's needs (print vs. screen)
• Larger files typically compress better

When to Use Each Level

• Low: Marketing materials, portfolios, photo albums, design presentations
• Medium: Business documents, reports, invoices, general correspondence
• High: Text documents, forms, contracts, internal memos, drafts

Quality Considerations

• Text remains sharp at all compression levels
• Images may show slight quality loss at high compression
• Vector graphics maintain quality at all levels
• Photos are most affected by compression
• Screen viewing requires less quality than printing

File Size Limits

Common file size limits to keep in mind:

• Email: 25MB (Gmail, Outlook)
• WhatsApp: 100MB
• Slack: 1GB
• Web Forms: Often 10-50MB

Alternative Solutions

If compression isn't enough:

• Split large PDFs into smaller files
• Remove unnecessary pages
• Convert to lower-resolution images first
• Use cloud links instead of attachments
• Consider alternative formats (e.g., EPUB for text)

Technical Implementation

This tool uses pdf-lib, a powerful JavaScript library for PDF manipulation. Compression is performed entirely in your browser using object stream compression and PDF optimization techniques. The library removes redundant objects, optimizes content streams, and applies efficient compression algorithms to reduce file size while maintaining document integrity.