How to Compress a Scanned PDF Without Making It Unreadable
Shrink image-heavy scanned PDFs using a practical quality check instead of guessing at compression settings.
Why scanned PDFs are different
A scanned PDF may contain one large raster image per page. Even when a page looks like text, the PDF can actually be storing millions of image pixels rather than compact font instructions.
That is why scanned files often respond strongly to image-based compression. The same process can also blur small characters if quality is reduced too far.
Choose quality by document purpose
For casual reading, a balanced preset can be sufficient. For legal, medical, financial or archival material, prioritize legibility over the smallest possible file.
Inspect the smallest important text on the page, not the title. Also check faint pencil marks, signatures, barcodes, stamps and shaded table cells because they can disappear before ordinary body text does.
Use a two-copy workflow
Keep the original scan untouched and create a separate compressed sharing copy. This gives you a lightweight file for email or portals without sacrificing the source image quality.
If the compressed result is still too large, consider splitting the document into logical sections rather than repeatedly compressing an already degraded copy.
Use the related Pageivo tool
Make large PDF files easier to share. The operation runs in your browser and does not require an account.
This guide provides general technical and workflow information. For regulated records, legal filings, security-sensitive data or organizational compliance, follow the rules that apply to your specific situation.