Compress PDF
Upload a PDF, choose a compression level, and download a smaller file — no sign-up required.
Drop a PDF to compress
Upload one PDF and reduce file size with a server-side compression pass.
or drag files here
Best for reducing file size before sharing or uploading. Compression strength affects visual quality.
Supported formats
Source PDF
Review the current PDF before compressing it.
No PDF loaded yet
Upload a PDF and its pages will appear here before compression starts.
Upload a PDF to begin
Upload one PDF and reduce file size with a balanced or stronger compression pass.
Compression level
Frequently Asked Questions
How do I compress a PDF online for free?
Upload your PDF to UsePDF.io, choose a compression level, and download the smaller file. No sign-up or software installation required.
How much can I reduce a PDF file size?
Depending on the content, PDFs can be reduced by 20% to 80%. PDFs with many images compress the most.
Will compression reduce the quality of my PDF?
The 'Low' compression setting preserves near-original quality. 'High' compression reduces file size the most with some quality trade-off.
What is the maximum file size I can compress?
Files up to 50 MB are supported.
Is my PDF safe when compressing online?
Yes. Files are processed securely and deleted from our servers immediately after compression.