Compress PDF Online
Reduce PDF file size online for free. Our browser-based compressor shrinks PDFs without quality loss — no sign-up, no uploads, fully private.
NEXT_PUBLIC_ADSENSE_PUBLISHER_IDNEXT_PUBLIC_ADSENSE_PUBLISHER_IDHow to use Compress PDF Online
Upload your PDF
Drag and drop your PDF into the drop zone. It is processed locally — nothing is uploaded.
Select compression level
Choose Low (best quality), Medium (balanced) or High (smallest file size).
Compress
Hit Compress PDF. The tool re-encodes content using pdf-lib directly in the browser.
Download compressed PDF
Your compressed PDF downloads automatically. Compare sizes before and after.
Frequently Asked Questions
Does compressing a PDF reduce quality?
At Low and Medium settings quality is visually indistinguishable from the original. High compression reduces image fidelity but produces the smallest files.
Is there a file size limit?
No server limits — your browser memory is the only constraint. Files up to 200 MB work on most modern devices.
Does this tool store my PDF?
Never. All compression is done client-side with WebAssembly. No data is sent over the network.
What compression algorithm is used?
The tool uses pdf-lib to remove redundant cross-reference tables and re-compress embedded images with a lower quality factor.