How to compress a PDF (without losing quality)
Most PDFs are big because of one thing: embedded images. Text and vector paths compress almost for free.
The three levers
- Downsample images to the resolution you actually need (150 DPI for screen, 300 DPI for print).
- Re-encode photos as JPEG at ~75% quality; keep line art as PNG/CCITT.
- Subset fonts — remove glyphs the document doesn't use.
What we do
Our Compress PDF tool runs Ghostscript server-side (25 MB limit, 5/day free) with an /ebook preset — a good default that hits ~40–70% shrink on image-heavy PDFs. For text-only PDFs, use Merge / Rewrite — rewriting with pdf-lib alone often shaves 10–20% by removing bloated metadata.