PDF Compressor
Reduce the file size of a PDF by re-rendering each page as a compressed image. Upload a PDF, choose a compression level, and download a smaller file.
This compresses PDFs by converting each page into an image, which shrinks file size significantly for scanned or image-heavy documents - but the resulting text is no longer selectable or searchable.
Click to upload a PDF file
Your file is processed entirely in your browser
Recommended Settings
Pro Tips
- •This works best on scanned or image-heavy PDFs, since it recompresses the visual content of every page as a JPEG
- •Text-based PDFs (already efficient at the byte level) may not shrink much and can occasionally grow slightly larger after rasterization
- •High Compression uses a lower resolution and JPEG quality, dramatically reducing size at the cost of visual sharpness
- •The resulting PDF's text is no longer selectable or searchable, since every page becomes a single embedded image
Most Popular
Most users start with Medium Compression, then try High if the file is still too large
When to Use This Tool
Shrink a large PDF so it fits within email attachment size limits before sending it.
Reduce a scanned document's file size to speed up uploads to forms, portals, or cloud storage with size restrictions.
Compress a large batch of scanned PDFs to save disk space or reduce cloud storage costs.
Make a multi-page scanned document more practical to share by significantly cutting its file size.
How It Works
Read the uploaded PDF file as binary data directly in your browser and record its original size
Parse the file into a PDF document using the PDF.js library
For each page, render its full content onto a canvas at a resolution matched to the chosen compression level
Compress each rendered page into a JPEG image at the corresponding quality setting
Rebuild a new PDF using pdf-lib, embedding each compressed page image at its original page size, and compare the resulting file size to the original
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by PDF.js + pdf-lib for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
Why is the text in my PDF no longer selectable after compression?
This tool compresses PDFs by converting each page into a single JPEG image, which is how it achieves significant size reduction on scanned or image-heavy documents. Since the page becomes an image, the original text layer is no longer present.
Why didn't my file get much smaller (or got bigger)?
PDFs that are already mostly text with minimal images are typically very space-efficient, so converting them to images doesn't help and can occasionally increase file size. This tool works best on scanned documents or PDFs with large embedded photos.
What's the difference between the compression levels?
Low Compression renders at a higher resolution and JPEG quality for the best visual result with a smaller size reduction. High Compression uses a lower resolution and more aggressive JPEG quality for the smallest possible file, at the cost of visual sharpness.
Is my PDF uploaded to a server?
No. The entire file is read, rendered, recompressed, and reassembled locally in your browser. Your document never leaves your device.
Will compression affect image quality significantly?
Yes, to varying degrees depending on the compression level chosen. Since every page becomes a JPEG, you'll see some quality loss, more noticeable at higher compression levels - review the result before relying on it for archival purposes.