Protect PDF

Add a password to your PDF file to prevent unauthorized access. Secure your sensitive documents instantly online — no signup needed.

Add Password to PDF — Lock Your Documents

Use ModifyPDF's Protect PDF tool to add strong encryption to your files and prevent unauthorized viewing. It's free, fast, and doesn’t require installation or login.

Why Password-Protect a PDF?

Prevent unauthorized access to private documents
Comply with data privacy for personal or legal files
Secure sensitive content like reports, contracts, or eBooks

How to Protect a PDF

Upload your PDF file
Enter a password
Click Protect PDF
Download your newly secured file

File Security

Your files are processed in real-time and deleted automatically. Passwords are not stored anywhere.

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FAQs

What type of encryption is used?

Standard PDF password protection with 128-bit encryption using PyPDF2.

Will this work on scanned PDFs?

Yes, any valid PDF file can be protected regardless of content type.

Can I remove the password later?

Yes, use our Unlock PDF tool to remove it.