PDF & Docs5 min readUpdated 2026-05-18
How to Reduce PDF File Size Without Blurring Text or Certificates
Section 01
Why Scanned PDFs Become Bloated
When a scanner captures a paper document at 600 DPI, it saves every page as a massive uncompressed color photo inside a PDF wrapper.
PixEnhance PDF engine analyzes embedded raster streams, downsamples excessive DPI to 150 DPI, and applies smart JBIG2/JPEG compression to drop file size by 80%+ instantly.
Official Reference Table
Reference Specifications & Dimensions
| Compression Level | Original PDF Size | Compressed Size | Text Sharpness |
|---|---|---|---|
| Low (High Quality) | 12.4 MB | 2.8 MB | 100% Original Vector |
| Recommended | 12.4 MB | 480 KB | Crisp & High Readability |
| Extreme (Smallest) | 12.4 MB | 190 KB | Acceptable for Screen Review |
Scroll horizontally on mobile devices to view all table columns.
Summary • Key Takeaways
- Scanned PDFs contain raw uncompressed image streams that make files huge.
- Smart PDF compression re-encodes image streams while keeping vector fonts intact.
- Real Example: A 12.4 MB scanned certificate PDF was compressed down to 480 KB with 100% readable text and official seals.
Frequently Asked Questions
Important answers regarding exam rules, dimensions, and optimization.
Can I compress a password-protected PDF file?
You must unlock or remove password protection first before compressing, as encrypted streams cannot be re-encoded.
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