Protect PDF
Lock a PDF with a password using strong AES encryption.
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Your files are processed on your device and are never uploaded to our server.
About Protect PDF
Add a password to a PDF so only people who know it can open the file. The tool uses 256-bit AES encryption, the same standard used by Adobe Acrobat, and works with every modern PDF reader.
How to use Protect PDF
- 1Select your PDF.
- 2Type a password and type it again to confirm.
- 3Click "Protect PDF" and download the locked file.
Why use this tool?
- Private. Files never leave your device.
- Free. No sign up, no limits, no watermark.
- Fast. Results in seconds, no waiting in a queue.
- Any device. Works on computers, tablets and phones.
Frequently asked questions
What happens if I forget the password?
There is no way to recover it. Keep a copy of the original file or save the password somewhere safe.
Is my password sent anywhere?
No. The encryption happens in your browser. We never see your file or your password.
How strong should my password be?
Use at least 10 characters with a mix of words, numbers and symbols. Our Password Generator can make one for you.