PDF compression guides
How PDF compression actually works, what it costs in quality, and how to get a file small enough to send — with numbers from our own tests.
- How kompakt compresses PDFs inside your browserNo server, no upload: pdf.js renders each page to a canvas, the canvas becomes a JPEG, and a 70-line writer streams the JPEGs into a new PDF. What that buys you, what it costs, and the bugs we found measuring it.9 min read
- PDF compression vs quality: what you lose at 72, 120 and 200 dpiWe compressed four kinds of PDF at every setting, in the browser and with Ghostscript, and measured size, speed and whether text survived. Side-by-side crops included.7 min read
- Why is my PDF so large? 5 causes and what to do about eachA 20-page text report can weigh under 100 KB while a 6-page scan weighs 3 MB. Here is what actually takes up space inside a PDF, how to tell which case you have, and which fix works.6 min read
- How to make a PDF small enough to emailGmail and Outlook.com both cap attachments at 25 MB, and encoding eats part of that. How much smaller your PDF needs to be, and the fastest way to get there.4 min read