100% Client-side

Protect PDF

Add password protection to your PDF. Nothing is uploaded, processing runs entirely in your browser.

or drop PDF here

Any size works

0 KB uploaded. Your file never leaves this browser tab.

Open your browser's Network tab while you use this tool, you will see zero data sent to any server.

IYONM

Cloud tools

Your files

Stay on your device

Uploaded to a server

File size limit

None

Capped on free plans

Works offline

Yes

Signup

Never

Pushed for limits

How to use

📄

1. Upload PDF

Select the PDF you want to protect.

🔑

2. Set password

Enter and confirm your chosen password.

🔒

3. Download

Save your password-protected PDF.

Is encryption done in the browser?

Yes. Your PDF is processed entirely client-side. No files are uploaded.

What password strength is required?

We recommend at least 8 characters mixing letters, numbers, and symbols.

Can I unlock the PDF later?

Yes. Use our Unlock PDF tool to remove the password.

Is this compatible with all PDF readers?

Yes. The protected PDF can be opened with Adobe Reader, Preview, and other standard PDF viewers.