I recently had to shrink some PDF files to send to be able send them by email.

Shrinking a PDF

TL:DR

gs -q -sDEVICE=pdfwrite -dCompatibilityLevel=1.7 -dPDFSETTINGS=/ebook -dNOPAUSE -dBATCH -sOutputFile=out.pdf in.pdf

Let's break is down !

gs stands for Ghostscript, a suite of tools …