Compress PDF Online Free
Reduce your PDF file size. Upload one PDF and download a smaller version.
Drop a PDF file here
or
Your files never leave your browser
How to Compress a PDF
Upload PDF
Select or drop the PDF file you want to compress.
Compress
Click Compress and wait while we optimize the file in your browser.
Download
Download your smaller PDF and see how much space you saved.
Frequently Asked Questions
How much can I reduce the file size?
Results vary depending on the PDF content. Files with many images typically compress more than text-heavy documents. Some text-only PDFs may only shrink a few percent.
Will compression affect quality?
Our tool optimizes the PDF structure without aggressively re-encoding images, so visual quality typically stays the same. Always preview the output before sending important documents.
Is my file uploaded to a server?
No. Compression happens entirely in your browser. Your file never leaves your device.
My PDF is too large for email — will this fix it?
Often yes. If your file is slightly over the limit (e.g. 12 MB on a 10 MB cap), compression may bring it under. Extremely large scanned documents may need splitting instead.
Can I compress a merged PDF?
Yes. Merge your files first, then compress the combined document for a smaller final attachment.
Does it work on scanned PDFs?
Scanned PDFs are image-heavy and may compress moderately. For best results with scans, consider lowering scan resolution at the source.
Reduce PDF File Size Without Losing Quality
Large PDF files can be difficult to email, upload, or share. Site95's free PDF compression tool optimizes your document structure to reduce file size while preserving visual quality. Perfect for shrinking scanned documents, presentations, and image-heavy PDFs — privately in your browser, with no account and no watermark.
When compression helps most
PDFs exported from PowerPoint or InDesign with embedded graphics often shrink noticeably. Multi-page color scans benefit when internal structure is bloated. Government forms and text-heavy contracts may see smaller gains but are still worth trying before splitting a file or using overnight delivery of a USB stick.
Email attachment limits
Gmail allows roughly 25 MB per attachment; Outlook and corporate servers often enforce 10–20 MB. If you see "message too large," compress first. Our tool shows original size, new size, and percentage saved so you know immediately whether the result fits your limit. If one pass is not enough, try a stronger compression level or split the PDF into smaller parts.
What to expect from browser compression
Results vary by how the PDF was created. Text-only files may shrink modestly. Image-heavy scans can shrink a lot. Always open the downloaded file and spot-check a few pages before sending it to a client or school portal. Keep the original until you are happy with the output.
Privacy for sensitive documents
Tax returns, pay stubs, and medical records should not be uploaded to unknown servers. Site95 compresses locally in your browser — the same privacy advantage as our merge and split tools.
See our complete guide to compressing PDFs for email for troubleshooting and best practices.