Compress PDF — Free Online Tool

Compress PDF reduces the size of large PDF files by re-compressing embedded images while keeping text sharp and readable. Choose a quality level that balances size and appearance, then download the smaller file. Ideal for emailing documents, uploading to portals with size limits, or archiving scanned papers. PDFStudio Pro runs compression 100% in your browser — no uploads, no account, no watermark. Compatible with modern desktop and mobile browsers.

Open Compress PDF tool now

Step-by-step instructions

Open Compress PDF.
Upload your PDF.
Choose a compression quality level.
Download the smaller PDF and compare sizes.

Supported formats

PDF (.pdf).

Privacy & security

Files are processed locally in your browser. We do not operate an upload endpoint for this tool. Temporary data is released when you leave the page. The site is served over HTTPS. See our Privacy Policy.

Pricing & workflow

Price: Free forever — no limits, no watermark. Workflow: open tool → add file(s) → process in browser → download. Works offline for most operations once libraries are loaded. Compatible with Chrome, Edge, Firefox and Safari on desktop and mobile.

Frequently asked questions

Is Compress PDF free?

Yes. Unlimited use, no registration, no watermark.

Are my files uploaded?

No. Processing is 100% in-browser.

Can I use it on mobile?

Yes, on modern mobile browsers.

Is there a file size limit?

We do not set a server limit. Practical limits depend on your device memory.

Does it add a watermark?

No. Output contains only your content.

Why use Compress PDF on PDFStudio Pro

Compress PDF on PDFStudio Pro reduces file size by re-compressing embedded images while keeping text sharp when possible. Choose a quality level that balances size and appearance, then download the smaller PDF. Ideal for emailing documents, uploading to portals with size limits, or archiving scans. Processing stays in your browser — no uploads, no account, no watermark. If you still need a smaller file after a normal pass, try Extreme Compress PDF for maximum reduction.

Tips for better results

Start with Balanced or High quality. Compare the new size with the original. Scanned colour documents often shrink more with a stronger level or by converting to grayscale first. Keep a copy of the original until you confirm the output opens correctly. Works on modern desktop and mobile browsers.