Locking a PDF with a password prevents anyone without the password from opening it. Here is how to lock any PDF for free in seconds.
Navigate to the protect tool in any browser. Works on Windows, Mac, iPhone, and Android.
Upload your PDF and enter a strong password. RC4-128-bit encryption is applied automatically.
Tip: Use at least 12 characters mixing letters, numbers, and symbols. Never share the password in the same email as the locked PDF.
Download the locked PDF. Only someone with the password can open it in any PDF viewer.
RC4-128-bit — supported by Adobe Acrobat, Apple Preview, Foxit, Chrome, and all modern PDF viewers.
Yes — 100% free at pdfeditor.onl/protect-pdf, no account required.