Reduce your PDF file size by up to 90% while maintaining visual quality with FunPDF's Compress PDF tool.
Step-by-Step Guide
1. Upload Your PDF
Upload your PDF file to the FunPDF Editor:
Using Drag and Drop:
- Drag your PDF file into the editor window
- Drop it anywhere on the page
- The file loads in File View mode (compression works on complete documents)
Using Upload Button:
- Click "Upload PDFs" or "Add files" button in the left sidebar
- Select your PDF file (up to 200MB)
- Click "Open" to upload
The file size is displayed in the sidebar - note it for comparison after compression.
2. Select Compress PDF Tool
- Open the Compress PDF tool from the right sidebar
- Or select it from the tools dropdown menu
- The compression settings panel appears
3. Choose Compression Level
Select one of three compression levels:
Low Compression (Best Quality)
- File size reduction: 20-40%
- Quality: Maximum quality preserved
- Minimal quality loss
- Best for: Professional documents, portfolios, documents for printing
Medium Compression (Balanced) - Recommended
- File size reduction: 40-70%
- Quality: Very good quality maintained
- Best balance of size and quality
- Best for: General documents, email attachments, most everyday use
High Compression (Smallest Size)
- File size reduction: 60-90%
- Quality: Good quality with some trade-offs
- Images may show slight quality reduction
- Best for: Web upload, storage optimization, when file size is critical
4. Optional: Rotate PDF
If your PDF orientation needs fixing:
- Use the rotation option before compressing
- Rotate pages to correct orientation first
- Then compress the properly oriented PDF
5. Compress PDF
Click "Compress PDF" to start:
Small Files (≤10MB):
- Process instantly on the server
- Files are not stored
- Results appear within seconds
Large Files (>10MB):
- Uploaded to secure temporary storage
- Processed in background with real-time progress
- Progress bar shows processing status
- Files automatically deleted after 2 hours
6. Review Results
After compression completes, you'll see:
- Original file size
- New compressed file size
- Compression percentage achieved (e.g., "Reduced by 65%")
7. Download Compressed PDF
- Click "Download" to save the compressed file
- The file is significantly smaller while maintaining quality
- Compare quality with the original if needed
Understanding Compression
How Compression Works
FunPDF's smart compression algorithms optimize:
Images:
- Reduced image resolution while preserving clarity
- Smart image optimization without visible quality loss
- Larger images compress more effectively
File Structure:
- PDF linearization for faster web viewing
- Optimized internal structure
- Removed unnecessary data
Result: Smaller file size with minimal quality impact.
What Compression Does NOT Do
Compression does NOT:
- Remove pages, text, or content
- Delete visible information
- Change the document structure
- Make PDFs incompatible with readers
All information stays intact - it's just stored more efficiently.
When to Compress PDFs
Email Large PDFs
- Gmail limit: 25MB attachments
- Outlook limit: 20MB attachments
- Compress large PDFs to stay under limits
- Recipients get faster downloads
Speed Up Website Loading
- Reduce PDF sizes for online documents
- Faster page loading for visitors
- Better user experience
- Reduced bandwidth costs
Save Cloud Storage Space
- Google Drive, Dropbox, OneDrive
- Store more files in less space
- Reduce monthly storage costs
- Archive documents more efficiently
Meet File Size Requirements
- Job applications with size limits
- Grant submissions and academic portals
- Online forms with upload restrictions
- Government or institutional systems
Reduce Mobile Data Usage
- Smaller files use less mobile data
- Faster downloads on phones
- Better for slow internet connections
- Accelerate uploads and downloads
Compression Results by PDF Type
Text-Heavy PDFs
- Typical reduction: 20-50%
- Text stays sharp and clear at all compression levels
- Quality loss minimal even with high compression
- Already efficiently stored (text is compact)
Image-Rich PDFs
- Typical reduction: 70-90%
- Images compress most effectively
- Medium compression recommended for balance
- High compression may reduce image clarity slightly
Scanned PDFs
- Typical reduction: 30-60% (varies widely)
- Already compressed in most cases
- Results depend on original scan quality
- May see limited additional compression
- Still worth trying - often achieves meaningful reduction
Mixed Content PDFs
- Typical reduction: 50-70%
- Combination of text and images
- Medium compression works well
- Balanced quality and size reduction
Tips for Best Results
Choose the Right Level
- Start with medium compression (recommended)
- Compare results with original
- Adjust level if needed
- Keep original file as backup
Compress Before Merging
- Compress individual PDFs first
- Then merge them together
- Results in smaller final file
- More efficient than compressing after merge
Test Quality
- Download and review compressed file
- Check image clarity and text sharpness
- If quality is too low, re-compress with lower level
- Keep original until satisfied with result
Rotate First
- Fix orientation before compressing
- Use rotation option in compress tool
- Avoid re-processing files
Troubleshooting
File Already Compressed
If compression achieves minimal reduction (< 10%):
- PDF is already well-optimized
- Limited additional compression possible
- Try splitting and removing unnecessary pages
- Consider keeping original file
Password-Protected PDFs
Cannot compress password-protected PDFs:
- Use Decrypt PDF tool first
- Enter the correct password
- Download unlocked PDF
- Then compress the unlocked file
File Too Large (>200MB)
If file exceeds 200MB limit:
Compression Too Aggressive
If high compression reduced quality too much:
- Upload original file again
- Choose medium or low compression instead
- Compare output before distributing
- Always keep original as backup
Processing Failed
If compression fails:
Privacy and Security
Small Files (≤10MB)
- Processed on server without storage
- Not written to disk
- Compressed and returned immediately
- Maximum privacy
Large Files (>10MB)
- Stored temporarily during processing
- Automatically deleted after 2 hours
- Gives you time to download result
- Files don't stay permanently
See Is My Data Secure? for full privacy details.
Next Steps
Start reducing your PDF file sizes with Compress PDF now!