Compress PDF Online – Reduce PDF File Size Free
PDFmuto compresses a PDF in your browser by repacking its data and removing redundant metadata. Nothing is uploaded to a server.
- No file limits
- No registration
- Free forever
- PDFs never leave your browser
Drop your PDF here
Supported format: PDF
Repacks the document and strips redundant metadata. Best on files bloated by office suites and repeated saves — pages keep their original quality.
How to Compress a PDF
Upload Your PDF
Drop the PDF you want to shrink onto the page or browse for it on your device.
Run the Compression
Click Compress. The tool repacks the document’s objects and strips redundant metadata to reduce its size.
Download Compressed PDF
Compare the before and after sizes, then download your smaller PDF. The original stays exactly as it was.
Why Compress PDFs?
Smaller PDFs email faster, upload quicker, and pass attachment limits. A bloated scan can often drop to a fraction of its size.
Compression here is lossless for content: pages keep their original quality. You get a smaller file without re-encoding images or text.
PDF Compression Methods
| Method | Object repacking + metadata cleanup |
|---|---|
| Quality | Preserved, no image re-encoding |
| Output | Smaller PDF |
| File size limit | None, limited only by your browser |
| Upload | None, processed on your device |
Your PDFs never leave your browser
All processing happens locally on your device. Nothing is uploaded to a server, stored, or tracked.
Frequently asked questions
How much will my PDF shrink?
It depends on the file. In our compression benchmark of 8 public-domain documents, the median reduction was 2.7% and the best result was 31.1% — on a bloated editor-saved file. Already-tight files may barely shrink or even grow slightly.
How do you know the compression works?
We publish a reproducible compression benchmark: 8 public-domain documents, 6,059 pages, processed with the same pdf-lib settings this tool uses. Median reduction was 2.7%. See the full methodology and results table on our compression benchmark page.
Does compression reduce quality?
This tool repacks the document without re-encoding images, so visual quality stays the same. For aggressive lossy compression you would need to re-encode images.
Is the original file modified?
No. You download a new compressed copy and the original stays exactly as it was.
Learn more about PDFs
Read practical guides for working with PDFs without uploading your files. Browse all guides →