Compare software

pdfsizeopt vs Smallpdf: catalog facts
pdfsizeopt	Smallpdf
Free Free and open source.	Freemium A limited free tier is available. Pro is a paid subscription.
Windows, Linux, Command line	Windows, Android, iOS, Web
Lossless size reduction Docker image available	Clean, fast interface that covers the common PDF chores Desktop and mobile apps alongside the browser tools
Command-line only Updates are infrequent	Free use is capped at a couple of documents per day Files are processed on their servers
Downloadable app	Web application
Open source	Closed source
License: GPL-2.0	License not stated
No account needed	Not stated if an account is needed
Works offline	Not stated if it works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked September 22, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.