Reduce PDF file size online
Upload your PDF file, choose compression quality, and reduce file size while maintaining document quality. Fast, secure, and completely free to use.
Drag and drop PDF files here or click to select
You can upload multiple files at once
When to Compress PDF Files
Email Attachments
Reduce file size to meet email attachment limits and send faster
Cloud Storage
Save storage space when uploading documents to cloud services
Mobile Devices
Make PDFs easier to view and share on smartphones and tablets
Web Publishing
Optimize PDFs for faster loading on websites and web applications
Compress PDF Features
Multiple Quality Levels
Choose between maximum compression, balanced, or best quality based on your needs
Real-time Preview
See original and compressed file sizes before downloading
No Quality Loss
Smart compression algorithms maintain document readability and quality
Browser-based Processing
All compression happens in your browser - files never leave your device
How to Compress PDF Files Online
1
Upload Your PDF File
Click the upload area or drag and drop your PDF file. File size can be up to 100MB.
2
Choose Compression Quality
Select from Maximum Compression (smallest file), Balanced (optimal), or Best Quality (preserve quality).
3
Click Compress PDF
Press the 'Compress PDF' button. Compression typically takes 10-20 seconds depending on file size.
4
Download Compressed File
Once compression is complete, click download to save your compressed PDF with reduced file size.
PDF Ninja Compress vs Alternatives
| Feature | PDF Ninja | Online Services | Premium Tools |
|---|---|---|---|
| Price | Free | $19.99/mo | $9/mo |
| Files uploaded | No | Yes | Yes |
| Max file size | 100MB | Unlimited | 5GB |
| Processing time | 10-20s | 30-60s | 20-40s |
| Quality levels | 3 levels | Advanced | 1 level |
| Watermarks | None | None | Yes (free) |