Protect PDF
Add a strong password to encrypt and secure your PDF documents. The encryption is done entirely in your browser; your files never leave your device.
1. Upload PDF Document
Click to upload or drag and drop
Upload a PDF file up to 50MB
2. Security Settings
The password will be required to open this PDF document. Do not lose it.
How In-Browser PDF Encryption Protects Sensitive Files
Discover how client-side cryptographic hashing secures confidential financial and legal records:
Standard PDF Security Handlers
Encrypts the document dictionary using ISO 32000 standard encryption handlers, locking page trees, bookmarks, and attachments behind password verification.
100% Client-Side Key Derivation
Your password and cryptographic encryption keys are computed in local browser memory. Neither your password nor your PDF is ever transmitted across the network.
Universal Acrobat Compatibility
Password-protected PDFs open seamlessly on Adobe Acrobat, Apple Preview, Google Chrome, Mozilla Firefox, Android, and iOS PDF viewers.
Frequently Asked Questions
Everything you need to know about password protecting PDF documents.
What happens if I forget the password?
Because our tool uses genuine cryptographic PDF encryption with zero server backdoors, forgotten passwords cannot be recovered. Ensure you store your password securely.
Is my password or PDF file sent to any server?
No. All encryption mathematical operations run 100% inside your web browser sandbox using WebAssembly and client-side JavaScript.
Can the protected PDF be opened on smartphones?
Yes. Standard PDF readers on iOS (Apple Files / Books) and Android (Google Drive / Adobe Reader) will prompt for the password when opening the document.