Optimize PDF
Compress PDF
Shrink PDF file size
Three quality presets — low / medium / high — to balance size and clarity. Runs in a Web Worker so the UI stays smooth.
Browse all toolsFiles processed in your browser — never uploaded
In your browser
Files never leave your device.
Instant
No signup, no upload queue.
Free forever
All tools, no paywall, no watermarks.
No tracking
We don't keep or analyze your files.
How to use Compress PDF
Step 1
Drop the PDF
Add the file you want to optimize. Encrypted PDFs work too.
Step 2
Pick a quality preset
Balance file size against visual quality with one click.
Step 3
Optimize in-browser
The PDF is repacked locally — no upload, no waiting in a queue.
Step 4
Save the result
Compare the before/after size and download the new copy.
Frequently asked questions
Everything we get asked most often about Compress PDF.
How much smaller will my PDF get?
Image-heavy PDFs often shrink 50-80%. Text-only PDFs may only shrink a few percent because they are already efficient.
Which preset should I choose?
Use Balanced for email and web sharing, Light for archival quality, and Strong when you need the smallest possible file.
Are my files uploaded to a server?
No. Every conversion runs inside your browser using WebAssembly. Your files never leave your device — not even temporarily.
Is the output watermarked or limited?
No watermarks, no signup wall, no size cap beyond what your browser can handle. Every download is yours, plain and unbranded inside the file.
Does this work on mobile?
Yes. The tool works in any modern browser on iOS, Android, Windows, macOS, or Linux. Large files may run faster on a desktop, though.