How PDF Compression Works in Practice

Find what makes the file large

Scanned images, embedded fonts, duplicate resources, and high-resolution graphics are common causes. Text-heavy PDFs may already be compact, leaving little room for safe reduction.

Balance size and usability

Downsampling images can deliver large savings, but excessive compression makes small type and diagrams unreadable. Test normal screen zoom and a representative print. Preserve selectable text where possible instead of rasterizing whole pages.

Check features after compression

Verify links, forms, bookmarks, transparency, accessibility tags, and signatures. Compression or rewriting can invalidate digital signatures. Keep the original and name the smaller output separately until it passes review.