Protect PDF
Add a password to encrypt a PDF.
100% Free. No sign-up, no watermarks, no limitsDrop a file here, or browse
PDF · APPLICATION/PDF
Protect PDF — Free Online Converter
Contracts, statements, anything you'd rather not leave unlocked: set a password and the file is encrypted with AES-256, so only someone who knows it can open the PDF at all.
How to password protect a PDF in 3 steps
- 1Drag your PDF into the box above, or click to browse.
- 2Choose a password to lock the document.
- 3Download your password-protected PDF instantly.
Frequently asked questions
How strong is the protection?
Your PDF is encrypted with AES-256, the same standard used for sensitive documents. Anyone opening it will need the password you set.
What happens if I forget the password?
We never store your password or your file, so we can't recover it. Keep the password somewhere safe — without it the PDF can't be opened.
Is Protect PDF really free?
Yes — Protect PDF is 100% free. There's no account to create, no subscription, no trial, and no daily limit. Convert as many files as you like.
Are my files safe and private?
Your files are processed in memory and never stored on our servers. Any temporary files are deleted automatically right after processing finishes.