Uploading tax documents, identity proofs, and academic transcripts to government portals is notoriously frustrating due to strict 100KB to 500KB file size limits. A standard smartphone camera scan of a document can easily exceed 5MB, resulting in instant rejection by portal uploaders.

1. Why Scanned PDFs Become Bloated

When you scan a physical document using a mobile application, the resulting PDF is often essentially a high-resolution, uncompressed JPEG wrapped inside a PDF container.

• Excessive DPI (Dots Per Inch): Smartphones capture images at 300 to 600 DPI. For on-screen reading, anything above 150 DPI is wasted data.
• Color Depth: Scanning a black-and-white text document in 24-bit RGB color triples the byte size compared to 8-bit grayscale.

2. Safe Client-Side Compression Techniques

Because these documents contain highly sensitive Personal Identifiable Information (PII), using random online PDF compressors is a massive security risk. Client-side compression tools modify the PDF safely in your browser memory by downsampling raster images to 144 DPI and removing unused metadata objects.

3. Best Practices for Legible Compression

To ensure your compressed document is still accepted by government reviewers, always prioritize grayscale conversion over aggressive lossy artifacting. A crisp black-and-white document at 1MB compresses better and reads clearer than a blurry color document at the same size.