How to compress high-resolution images in a pdf document
- Step 1Upload the high-resolution PDF — Drop the print-quality PDF into the compressor.
- Step 2Set the target image DPI — Choose 150 DPI for quality web display or 72 DPI for maximum compression.
- Step 3Apply compression — Images are downsampled to the target DPI and re-encoded.
- Step 4Download the web-optimised PDF — Save and publish the compressed PDF.
Frequently asked questions
What DPI is appropriate for screen-only PDFs?+
72 DPI matches standard screen resolution. 96-150 DPI gives sharper text and images on high-density (Retina) displays.
Should I keep the original high-resolution PDF?+
Always retain the original. Only use the downscaled version for web or email distribution — print production always requires the full-resolution original.
Will charts and vector graphics be affected?+
Vector elements in PDFs are not affected by image DPI settings — only raster images are resampled.
Privacy first
All PDF processing runs locally in your browser using PDF-lib and pdf.js. No file is ever uploaded — only metadata counters are saved for signed-in dashboard stats.