Compress PDF — Reduce File Size Without Uploading
Large PDFs are a common problem. Scanned documents, image-heavy reports, and print-ready files often balloon to 20–50 MB or more. This makes them slow to email, expensive to store, and difficult to upload to platforms with file size limits.
This Compress PDF tool re-renders each page at a chosen quality and resolution, then rebuilds the PDF. At the Balanced setting, most PDFs shrink by 50–70% with minimal visual loss. Everything runs in your browser — no uploads, no server, complete privacy.
How PDF Compression Works
There are two main approaches to PDF compression:
1. Image re-encoding (this tool's method)
Most PDF file size comes from embedded images — photos, scans, screenshots. This tool:
- Renders each PDF page to a high-resolution canvas
- Re-encodes that canvas as a compressed JPEG
- Rebuilds a new PDF with the smaller images as full-page backgrounds
Advantage: Works on any PDF, achieves dramatic reductions (up to 90%).
Trade-off: Text becomes part of the image (not selectable/searchable).
2. Structure optimization (alternative method)
Some tools preserve text by only recompressing embedded images and removing redundant data. Files shrink less (usually 10–40%) but stay fully searchable.
| Method | Size Reduction | Text Selectable? |
|---|---|---|
| Image re-encoding (this tool) | 50–90% | No |
| Structure optimization | 10–40% | Yes |
Text becomes non-selectable
- If you need searchable/copyable text, this compression flattens pages to images
- For searchable output, use a structure-optimizing tool instead
- Visual quality is preserved — you can still read everything
How to Compress a PDF in 3 Steps
-
Upload your PDF
Drag and drop a PDF into the tool above, or click Choose PDF. Files up to 100 MB are supported.
-
Choose compression level
Select High Quality (best visuals, moderate savings), Balanced (recommended), or Maximum Compression (smallest file, lower quality). Preview the estimated savings before clicking.
-
Download the compressed PDF
Click Compress PDF. The tool renders each page, re-encodes images, and rebuilds the file. Once complete, click Download Compressed PDF.
Compression Levels Explained
High Quality
Best for: Documents you'll print or share professionally.
Settings: 1.5× resolution, quality 0.85.
Expected size: 20–40% smaller than original.
Balanced (Recommended)
Best for: Email attachments, cloud storage, everyday sharing.
Settings: 1× resolution, quality 0.75.
Expected size: 50–70% smaller with no visible quality loss on screen.
Maximum Compression
Best for: Archival, forms, receipts, or when file size is critical.
Settings: 0.75× resolution, quality 0.55.
Expected size: 70–90% smaller — best for scanned documents with photos.
Pro Tips
- Scanned documents compress dramatically — often 80–90% smaller
- Text-only PDFs barely shrink — they're already optimized
- Photo-heavy PDFs compress 60–80% at Balanced setting
- Preview before sharing — always verify readability after compression
Key Features
3 Compression Levels
High, Balanced, or Maximum — choose your size/quality trade-off.
Up to 90% Smaller
Scanned PDFs can shrink by 90% while staying readable.
Progress Preview
See page-by-page progress as the PDF is compressed.
Before/After Stats
See exactly how much space you saved.
100% Private
All compression in your browser — files never leave your device.
Any PDF
Works on scanned documents, reports, eBooks, invoices, and more.
When to Compress a PDF
- Email attachments — most email providers limit attachments to 25 MB
- Cloud storage — smaller files save space and sync faster
- Upload forms — government and job portals often require PDFs under 5 MB
- Website uploads — faster downloads and lower bandwidth costs
- Document archives — long-term storage without bloat
- Printing services — some printers have file size limits
- Mobile sharing — smaller PDFs load faster on slow connections
Related PDF tools
- Combine multiple PDFs first with Merge PDF
- Convert images to PDF with Image to PDF
- Extract PDF pages as images with PDF to Image
- Create a PDF from JPGs with JPG to PDF