Protect PDF with Password — Free & Online
Add AES-128 password protection to your PDF in seconds. No signup, no watermarks.
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🔒
Drop your PDF here — done in seconds
Click the button below to browse, or drag & drop
🔐 Your files never leave your session — auto-deleted in 60 min
What do you need to do next?
Frequently Asked Questions
How does PDF password protection work?
ZillyPDF uses FPDI to re-assemble your PDF and applies AES-128 encryption. The password is required to open the file. ZillyPDF does not store your password.
Is there a file size limit?
Yes, 50MB per file. Files are automatically deleted after 60 minutes.
Are my files kept private?
Yes. Your files are processed securely and never shared. All files are automatically and permanently deleted after 60 minutes.
Can I remove the password later?
You can upload the protected PDF back to ZillyPDF's other tools after entering the password in a PDF reader to unlock it first.