PDF Compressor
Updated June 1, 2025Reduce PDF file size while keeping quality, so documents are easier to email or host.
Select a PDF to compress
Features
- Reduce PDF file size while preserving quality
- Compression level control (low, medium, high)
- Display before and after file sizes
- Calculate percentage reduction
- Downsample embedded images
- 100% client-side compression
Common Use Cases
- Compress PDFs to meet email attachment limits
- Reduce file size for web uploads and sharing
- Optimize PDFs for faster download on websites
- Shrink scanned documents that are too large
- Batch compress for archiving or storage
PDF Compression Explained
PDF compression reduces the file size of a PDF document by optimizing images, removing redundant data, and using efficient encoding. This makes PDFs faster to upload, download, and share.
Compression methods: The main approach is downsampling embedded images—reducing their resolution while maintaining visual quality. Text and vector graphics are typically small and don't benefit as much from compression. Unused objects and metadata can also be stripped to save space.
Compression levels: Low compression preserves most quality with modest size reduction. Medium balances quality and size. High compression aggressively downsamples images for maximum savings—best when file size is the priority.
What to expect: PDFs with many high-resolution images will see the biggest reductions (50-80%). Text-heavy PDFs with few images may only shrink 5-15%. Scanned documents benefit significantly from compression.
Examples
Original: 25MB scanned PDF (300 DPI images)
Compression: Medium
Result: ~8MB (68% reduction)Original: 18MB PDF
Target: Under 10MB for email
Compression: High → 6.5MB resultOriginal: 12MB presentation PDF
Compression: Low
Result: ~9MB (25% reduction, near-original quality)Frequently Asked Questions
At low and medium settings, quality loss is minimal and barely noticeable. At high compression, you may see slight image degradation. Text and vector graphics remain sharp at all levels.
Results vary: Image-heavy PDFs can shrink 50-80%. Text-only PDFs may only compress 5-15%. Scanned documents benefit most since they contain large embedded images.
No! Each compression pass may further degrade image quality. Compress once from the original at your desired level. If the result isn't small enough, go back to the original and use a higher compression level.
No. Text content is preserved during compression. Your PDF will remain searchable and selectable at all compression levels. Only embedded images are affected.
Low for archival/preservation. Medium for general sharing and web use. High for email attachments or when file size is the primary concern. Start with medium and adjust based on results.
💡 Tips
- Start with medium compression and test—adjust up or down as needed
- Always review the compressed PDF for acceptable quality
- Image-heavy PDFs benefit most from compression
- Keep the original uncompressed file for archival purposes