Password Protect PDF Online Free
Secure your PDF with password encryption
Encrypt your document with 256-bit password protection
Up to 35.00 MB per file • Single file
Your files never leave your device. Zero server uploads.
How It Works
Select File
Upload the PDF you want to secure.
Set Password
Enter a strong password. This password will be required to open the file.
Encrypt
Click "Protect PDF" to apply encryption and download your secured document.
Frequently Asked Questions
Quick answers about this tool
How secure is the encryption?▼
Can I set different permissions?▼
What if I forget the password?▼
Can protected PDFs be unlocked?▼
About This Tool
Password protect PDF files with our free PDF encryption tool. Add password security to prevent unauthorized access to sensitive documents. Our PDF password protection uses industry-standard encryption to secure contracts, financial reports, confidential proposals, or personal documents. Recipients must enter the password to open the file. Perfect for securing PDFs before emailing or sharing. The browser-based encryption ensures we never see your documents or passwords – 100% privacy. Always keep your password safe; recovery is impossible without it.
Why Choose AeroPDF?
100% Private
Processed entirely in your browser with no cloud uploads.
Instant Speed
No waiting for slow server roundtrips or queues.
Any Device
Works smoothly on Windows, Mac, iOS, and Android.