Compress PDF Online Free — Your Files Are 100% Secure
Shrink PDF file size online for free — lossless or high-compression. Secure and private — no signup, no watermark, no file limits.
Drop PDF files here
or
Max 25 MB per file · Secure and private — files are never stored
How it works
- 1Drop the PDF you want to shrink into the box
- 2Pick a compression level: Light, Recommended or Extreme
- 3Click "Compress PDF" — everything happens on your device
- 4Download the smaller file — or the original if it was already optimized
Frequently asked questions
Are my files uploaded to a server?
No. FileCPU runs entirely in your browser. Your PDF is read into memory, compressed locally, and handed back to you as a download. Nothing is ever transmitted or stored.
Which compression level should I choose?
Light re-saves the file without any quality loss — best when text must stay selectable and sharp. Recommended is the everyday choice: strong savings with quality that still looks great on screen. Extreme produces the smallest file by turning pages into images — fine for sharing, not for printing.
Why did my PDF barely shrink?
It depends what is inside. Text-and-vector PDFs shrink dramatically when rasterized. But scanned documents are already photographs in JPEG form, and well-made PDFs have little waste — Light mode especially may find almost nothing to remove.
What does "Already optimized" mean?
If compression cannot make the file smaller, FileCPU refuses to pretend otherwise: you get your original file back, untouched, with a note explaining why. We never hand you a "compressed" file that is actually bigger.
Is quality lost?
In Light mode, no — the content is identical. In Recommended and Extreme, pages are rendered to images at a chosen resolution and JPEG quality, so text becomes part of the picture: still perfectly readable on screen, but no longer selectable and softer when printed.
How many pages can I compress?
Documents up to 200 pages and 25 MB per file. The limits exist because all the work happens in your browser's memory.