PDF guides
Guides on PDF tools written to answer one concrete question each, with verifiable numbers and the date they were verified. No hedging, and no hiding the limits of our own tools.
Verified 2026-07-31
Six questions, six verified answers.
PDF tools compared
Who uploads your files to a server and who processes in the browser. List prices and real limits.
GuidesHow to tell if a site uploads your PDF
The Network tab test in under a minute, and the six signals that tell local from server.
GuidesPDF too big to email
The real limits of Gmail, Outlook and the rest, and why 25 MB is not 25 MB.
GuidesWhy some PDFs shrink 80% and others not at all
What compression actually does, the three levels with exact DPI, and when splitting is better.
GuidesPDF passwords: what actually protects
The two PDF passwords, the four ciphers, and why one of them comes off with a click.
GuidesElectronic signatures: the three levels
What a drawn signature is worth, when you need a qualified one, and what EU law says.
Need the tool, not the guide?
All twelve tools run in your browser. Compressing is free, no account.
Open the tools