When you should compress a PDF
Large PDFs break email limits, slow uploads to portals, and waste storage. Compression helps when you need to:
- Send a multi-page scan under 10–25 MB
- Meet government or university upload caps
- Share a deck that is mostly screenshots
What “good” compression looks like
Aim for the smallest file that still:
- Keeps body text readable at 100% zoom
- Preserves charts you need to print
- Doesn’t introduce heavy JPEG blockiness on photos
A simple workflow
- Open Compress PDF in ButterPDF
- Drop your file (it stays on your device)
- Choose a balanced quality target first
- Download and spot-check a text page and an image page
If the result is still large, compress again at a slightly lower quality — or split the document with Split PDF and send only what is needed.
Pro tip for scanned documents
Scans are often huge because every page is a high-DPI image. OCR (OCR PDF) can help you search text later; compression helps you share the file today.