How to Reduce a Scanned PDF File Size
Learn why scanned PDFs become large and how to reduce their size without making forms and signatures unreadable.
Why scanned PDFs are so large
Scanned documents store each page as an image. High resolution, color pages, and empty margins can make a short scan large. Compression is usually most effective on this kind of file.
How to compress a scanned PDF
Try the client-side PDF compressor · Convert PDF pages to images
- Choose the scanned PDF in the compressor.
- Select a moderate quality setting first.
- Download the result and inspect small print, stamps, and signatures.
- Lower quality again only if the file is still too large.
When to rescan instead
If the scan is crooked, blurry, or full of background noise, compression cannot restore missing detail. Rescan at a sensible resolution, use grayscale for monochrome forms, and crop empty margins.
Privacy note
Scanned IDs, contracts, and forms can contain sensitive information. A browser-local workflow avoids sending the file to a remote processing service.