๐ PDF Security
Password Protect PDF โ Keep Documents Secure Free
Add a password to any PDF to prevent unauthorised access. Free, instant and completely private.
Protect PDF
โ Free ยท No signupDrop your file here
or click to browse
Your file is processed locally in your browser โ never uploaded to any server
How It Works
1
Open Protect PDF
Go to curopdf.com/protect-pdf.
2
Upload your PDF
Select the document to protect.
3
Set your password
Enter and confirm your chosen password.
4
Download & share safely
Send the PDF separately from the password.
How to Password Protect a PDF
A password-protected PDF cannot be opened without the correct password. This prevents unauthorised access if the file is forwarded, intercepted or stored in a shared location.
Password security tips
- Use a password of at least 12 characters with a mix of letters, numbers and symbols
- Never send the password in the same email as the PDF
- Use a password manager to store the password securely
- Keep a record of the password โ a protected PDF cannot be recovered without it
Frequently Asked Questions
Is this tool really free?
Yes โ 100% free with no signup, no subscription and no limits.
Are my files stored anywhere?
Never. All processing happens in your browser. Files never leave your device.
Is it secure?
Yes. PDF.js (Mozilla's open-source library) runs locally and ignores scripts inside PDFs.
Does it work on mobile?
Yes โ iOS Safari 14+, Chrome and Firefox on Android fully supported.
What if I forget the password?
The PDF cannot be recovered without the password. Always record it securely.
Can I remove the protection later?
Yes โ use our Unlock PDF tool when you have the password.