Compress PDF Online

Reduce the size of your PDF files while maintaining optimal visual quality.

100% Local · Files never leave your device

IN: PDF FILEOUT: PDF · RECOMMENDED

100% LOCAL

Drop your file here or tap to browse

Processed directly inside your browser with zero server uploads

Choose file

How it works step by step

01Select or drag and drop the PDF file you wish to compress from your device.
02Choose your compression level (Recommended, Extreme, or Light).
03Click Process and download your compressed PDF instantly.

Technical specs & privacy

100% in-browser processing

Your confidential documents never upload to external servers. Optimization runs in your local browser memory.

Perfect for email attachments and portals

Meet strict upload limits for job applications, government portals, and email services.

Smart stream and metadata cleanup

Our engine cleans unreferenced objects, compacts text streams, and restructures internal tables.

Supported input formats	PDF FILE
Output target format	COMPRESSED PDF
Conversion engine	pdf-lib & PDF.js 2x Canvas (in-browser local)
Storage & Privacy	100% Local · Files never leave your device

Frequently asked questions

How does in-browser PDF compression work?

123FileTools uses a local WebAssembly engine that parses the PDF object graph, discards redundant data, and recompresses streams directly on your device.

Are my PDF documents uploaded to any servers?

Never. Everything is executed locally in your browser RAM. No files or personal data ever touch our servers.

What is the difference between compression levels?

Recommended strikes the ideal balance between file size and crispness. Extreme delivers the smallest size possible. Light maintains maximum visual fidelity.

Is this PDF compressor free?

Yes, 100% free with no file limits, no registration, and no watermarks.

1 MERGED PDF