How to compress a PDF without uploading it

Email attachments are often capped at around 20–25 MB, and many upload forms want much less. Scanned PDFs are the usual culprit: every page is a full-resolution photo.

Steps

1. Open the PDF Compressor.
2. Drop your PDF onto the page. It is read by your browser — it is not uploaded.
3. Pick a compression level (optionally convert to greyscale for even smaller scans).
4. Click Compress PDF, compare the new size, and download.

Tips

• Scans shrink the most. Pages that are already images compress very well.
• Text-heavy PDFs may not shrink much, because text is already compact. In that case, try removing pages you don't need with PDF Rotate & Organize.
• Compression re-encodes pages as optimised images, so text in the result may no longer be selectable. Keep the original if you need searchable text, or run PDF OCR afterwards.

Why do it locally?

PDFs are often contracts, payslips, IDs or medical records. A browser-based compressor means the file never leaves your device, and it keeps working offline once the page has loaded.