Password protect a PDF
Lock a PDF so only people with the password can open it. The file is encrypted with AES-256, a widely trusted encryption standard. Your password and your document never leave your device.
10 of 10 free online tasks left this hour · How your files stay private
- Files never leave your device
- Free, no sign-up
- No watermark added
Why use this free Protect PDF tool
AES-256
Strong encryption that opens in any PDF reader.
Password stays private
It is never sent anywhere, not even to us.
Works everywhere
The locked PDF opens in Acrobat, Chrome, Edge and phone apps.
Free
No sign-up and no watermark.
How to protect PDF in 3 steps
- 1
Choose the PDF you want to lock
- 2
Type a password twice
- 3
Download the protected PDF
Protect PDF: common questions
Your file is never uploaded. The tool runs inside your browser, so the file is read and changed on your own device. Nobody else, including us, can see it.
The PDF is encrypted with AES-256. Use a long password that is hard to guess.
The file cannot be opened without it, so keep it somewhere safe.
Yes, with Unlock PDF, as long as you know the password.
Yes. There is no sign-up, no watermark and no trial. You can run 10 tasks an hour online. For unlimited use, get the free desktop app for Windows or Mac.
Other free PDF tools
Need more than 10 tasks an hour?
The free YourOfficeSuite app for Windows and Mac has all 15 PDF tools with no limits, including Edit & annotate, Office to PDF and PDF to Word. It also has full Word, Excel and PowerPoint editors.