Hit a "file too large" error when emailing a PDF? Scanned documents and image-heavy files balloon quickly. Our free Compress PDF toolshrinks them in your browser — here's how to get the best result.
Why PDFs get big
Text is tiny; images are not. A PDF made of scanned pages is really a stack of photos, and photos are heavy. That's why scanned files are the ones that balloon.
What compression does
Compression rebuilds each page as an optimised image at a quality level you choose. For scanned and photo-based PDFs this cuts the size dramatically. Text-only PDFs are already small, so they may not shrink much — that's normal.
Picking a level
- Balanced — the best size-to-quality trade-off for most files.
- Strong — smallest file when quality matters less.
- Light — keeps pages looking their sharpest.
Still too big? Try splitting the document, or convert a colour scan to grayscale to save even more.