Protect PDF
Upload a PDF, set and confirm a password, then click "Protect PDF" to download an encrypted copy — free, private, and processed entirely in your browser.
About the Protect PDF Tool
Our free online Protect PDF tool adds strong password protection to any PDF file. It's useful for securing private, financial, or contract documents before sharing them by email or storing them on a shared drive, so only people who know the password can open them.
All encryption happens entirely inside your browser — your file and password are never uploaded to a server or seen by anyone else. That keeps things fast and your documents completely private, since they never leave your computer.
How to Protect a PDF
Step 1
Upload your PDF file
Select a PDF file from your device to add password protection to it.
Step 2
Set and confirm a password
Type your desired password twice to make sure it's entered correctly.
Step 3
Protect and download
Click "Protect PDF" and download your encrypted, password-protected file instantly.
Frequently Asked Questions
What type of encryption is used?
We utilize standard PDF encryption parameters supported natively by all PDF readers, including Adobe Acrobat, Chrome, and iOS Preview.
Is my password sent to a server?
No, all encryption processes run 100% locally in your web browser. We do not store or see your password.
What happens if I upload a PDF that's already password protected?
The tool will detect this and let you know the file is already protected, rather than overwriting its existing password.
Can I open the protected PDF without the password later?
No — once protected, the PDF requires the password to open in any standard PDF reader. Make sure to remember it, or use our Unlock PDF tool if you have the password and want to remove it again.
Does it cost money?
No. The Protect PDF tool is 100% free to use, with no registration or account required.