Why PDFs Get Large

PDFs grow large primarily because of embedded images. A scanned document at 300 DPI with full-resolution photos can easily exceed 50MB. Other contributors: embedded fonts, unoptimized vector graphics, and page metadata.

PDF Compression Methods

• Image resampling: Reduce embedded image resolution (e.g., 300 DPI → 150 DPI)
• Image recompression: Convert embedded images from uncompressed to JPEG
• Font subsetting: Only embed the characters actually used, not the entire font
• Object stream compression: Compress PDF internal structure

Step-by-Step: Compress PDF Online

1. Open PDF Compressor.
2. Upload your PDF.
3. Choose compression level: screen (smallest), print (balanced), prepress (best quality).
4. Download the compressed PDF.

What to Expect

A scanned 50-page PDF might go from 30MB to 5-8MB with moderate compression. A text-only PDF has limited compression potential (maybe 10-20% smaller). PDFs with many high-resolution photos see the most dramatic reductions.