Compress PDF Online
Reduce PDF file size while keeping your document clear, readable, and easy to share.
Drop your PDF file here
Compression Level
PDF Compressed Successfully
Your document has been optimized.
Original
0 KB
Compressed
0 KB
Saved
0%
Compression failed
We couldn't compress this file.
Reduce PDF Size Without Rebuilding Your Document
ScanPDF optimizes the PDF structure and supported resources while keeping the original document format intact.
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Structural optimization and garbage collection
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Stream and object deflation
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Image recompression and downsampling
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Measured size savings calculated instantly
What ScanPDF Preserves
Compression shouldn't mean destruction. Our smart PDF optimizer ensures your document remains fully functional.
Page Structure
Page count, page order, and page dimensions remain exactly as you uploaded them.
Document Content
Text, graphics, and images remain readable. Selectable text stays selectable.
Page Layout
Portrait or landscape pages, and original positioning of elements are safely preserved.
PDF Usability
The output is a readable, fully valid PDF structure that can be instantly downloaded.
How to Compress a PDF
Select Your PDF
Choose or drop the PDF you want to reduce.
Choose Compression
Select a compression level. We suggest Recommended for best balance.
Compress the PDF
Click COMPRESS PDF and allow ScanPDF to optimize the document.
Download the Result
Review the size reduction and download the compressed PDF.
Designed for Different PDF Documents
Reports
Reduce large reports for easier email sharing and archiving.
Scanned PDFs
Optimize image-heavy scanned documents efficiently with high compression.
Business
Compress proposals, statements and office PDFs for your clients.
Study Materials
Reduce notes, handouts and learning documents for easier storage.
Why Use ScanPDF Compress PDF
A simple, effective, and measured approach to PDF size optimization.
Simple Compression Flow
Upload, compress and download. No complicated settings required.
Measured Size Reduction
Compare the actual original and output sizes immediately.
Document-Aware
Compress the PDF without unnecessarily rasterizing the complete document.
Direct PDF Download
Download the verified compressed PDF immediately after processing.
Vector vs. Raster Compression Analysis
PDF compression efficiency depends heavily on whether your document contains vector geometry or embedded bitmap images:
Text & Vector PDFs
Digital PDFs with selectable text use mathematical curves. Stream deflation removes redundant structures, typically reducing size by 5% to 20% while keeping text pin-sharp.
Scanned & Image PDFs
Documents created from scanners or photo captures contain uncompressed bitmaps. ScanPDF downsamples these images, frequently achieving 50% to 80% reduction.
Encrypted Files
Password-protected documents cannot be decompressed or rewritten by server streams. Unlock or decrypt the file before submitting it for compression.
Technical Questions & Answers
Verified answers regarding PDF file compression mechanics.
Why did my PDF only shrink by a small percentage?
Documents composed primarily of digital vector text, embedded subset fonts, and minimal images are already compact. ScanPDF strips redundant metadata and deflates streams, but text geometry cannot be downsampled the way high-resolution raster images can.
What is the difference between Low, Recommended, and High compression?
Low preserves high image resolutions suitable for printing. Recommended balances crisp readability with significant byte savings for email attachments. High applies aggressive downsampling, best for meeting strict upload size limits on application portals.
Will PDF compression affect print quality or make text blurry?
Digital text, outlines, and vector lines remain perfectly sharp at any zoom level because they are rendered mathematically. Only embedded raster photos or scanned pages are re-sampled according to your chosen profile.
Can ScanPDF compress password-protected PDF files?
No. The compression engine must be able to read and rewrite internal object streams. If a file is encrypted with an open or permissions password, remove the password first before uploading.