How to Compress a PDF Without Losing Quality
Big PDF won't attach to an email or upload to a portal? Here's how to shrink it in your browser — no upload, no watermark — while keeping it readable.
Scanned contracts, image-heavy reports and exported slide decks can easily balloon past the 10–25 MB limits that email and upload forms impose. The fix is compression — and for most PDFs you can do it locally, without handing your document to a website.
Why PDFs get so large
The single biggest cause is images. A PDF made from phone photos or a flatbed scanner stores each page as a full-resolution picture. Ten pages at 300 DPI can be 20 MB on their own — the text and layout barely register by comparison.
What actually reduces the size
- Lower the image quality — dropping from 100% to 70% JPEG quality is invisible on screen but can halve the file.
- Reduce the resolution — a document only ever read on a screen doesn't need 300 DPI; 120–150 is plenty.
- Re-encode scanned pages — old scans are often stored inefficiently; re-compressing them recovers a lot.
Compress it privately, in your browser
Our PDF compressor renders each page, re-encodes it at the quality and resolution you choose, and rebuilds the file — all on your device. Nothing is uploaded, so it's safe for contracts, medical records and financial statements. You see the before-and-after size before you download.
Try the tool
Compress PDF