Secure & private
Zero server uploads. Every page is compressed on your own device, so confidential documents stay confidential.
🔒 100% browser-based · No uploads
Free Online PDF Compressor
Compress PDF is a free online PDF compressor. Compress PDF files and reduce PDF file size fast for email, web forms and sharing — 100% client-side, so your file never leaves your device.
Drag & drop your PDF here
or click to browse · PDF files only
Choose PDF File
Choose PDF File
PDF
Compression level
Fine-tune
Lower DPI = smaller file. 72 for screens, 150+ for printing.
JPEG re-encoding quality applied to every page.
Preparing…0%
Your PDF is processed locally in your browser and never uploaded.
Why use Compress PDF?
A fast, private PDF size reducer that works on any device — desktop, tablet or phone — without installing software.
Fast compression
No waiting in upload queues. Pages are processed instantly with live page-by-page progress.
Full control
Pick a preset or fine-tune DPI and JPEG quality to hit the exact file size you need.
Clear size metrics
See original vs. compressed size side by side with the exact percentage saved.
Works everywhere
Runs in Chrome, Edge, Firefox and Safari on Windows, macOS, Linux, Android and iOS.
Free, no sign-up
No accounts, no watermarks, no daily limits. Just drop a PDF and download the smaller version.
How to compress a PDF online
Reduce PDF file size in four simple steps:
- Upload your PDFDrag and drop a PDF into the upload zone or click “Choose PDF File”.
- Choose a compression levelSelect Low Compression (High Quality), Balanced or Extreme Compression — or adjust DPI and quality manually.
- Click “Compress PDF”Each page is rendered and re-encoded in your browser while the progress bar shows which page is being processed.
- Download the resultCompare original and compressed sizes, then click “Download Compressed PDF”.
PDF compression quality guide
Which setting should you use? Match the preset to where your PDF is going.
| Preset | DPI | JPEG quality | Typical savings* | Best for |
|---|---|---|---|---|
| Low Compression (High Quality) | 150 | 85% | 20–60% | Printing, archiving, detailed scans |
| Balanced | 110 | 70% | 50–80% | Email attachments, sharing, reading on screen |
| Extreme Compression | 72 | 45% | 70–95% | Web uploads, job portals, forms with size limits |
*Savings are largest on scanned and image-heavy PDFs. Text-only PDFs may not shrink because pages are converted into images.
Frequently asked questions
Everything you need to know about compressing PDFs with Compress PDF.
Is Compress PDF free to use?
Yes. Compress PDF is completely free with no sign-up, no watermarks and no file limits beyond what your device's memory can handle.
Are my PDF files uploaded to a server?
No. Compress PDF runs entirely in your browser. Your PDF is read, rendered and re-encoded on your own device and is never uploaded, stored or shared.
How does Compress PDF reduce PDF file size?
Each page is rendered with pdf.js at your chosen DPI, re-encoded as an optimized JPEG image at your chosen quality, and reassembled into a new PDF with jsPDF at the original page dimensions.
Can I compress a PDF without losing quality?
Use the High Quality preset (150 DPI, 85% JPEG quality) for results that look nearly identical on screen and print well, while still shrinking image-heavy or scanned PDFs significantly.
Which compression level should I choose?
High Quality is best for printing, Balanced is ideal for email and general sharing, and Extreme gives the smallest file for web uploads and forms with strict size limits.
Will the text in my compressed PDF still be selectable?
No. Because pages are rasterized into images, text in the compressed PDF is not selectable or searchable. Keep your original if you need editable or searchable text.
Why is my compressed PDF larger than the original?
Text-only or already optimized PDFs store text as compact vector data. Converting them to images can increase size. Try a lower DPI or the Extreme preset, or keep the original file.
More free PDF & file tools
Fast, private, browser-based productivity tools from the same family as Compress PDF.