Protect PDF
Encrypt your PDF with a password so only authorized viewers can open it.
Select PDF to Password-Protect
Encrypt your document with AES-256 password protection. Processed locally in your browser with zero server uploads.
How to Use Protect PDF
Upload File
Select the PDF to protect.
Set Password
Type a strong, memorable password.
Download
Save your password-protected PDF.
Key Capabilities
Local Execution
Applies standard AES-256 PDF encryption dictionaries client-side using the browser Web Crypto API.
- •Save your password in a password manager. Forgotten passwords cannot be recovered.
- •Do not close the tab before the encryption stream finishes saving.
PDF Security & Cryptographic Standards
Standard Cipher Specifications
Documents are protected using standard symmetric key cryptography (AES-256 or AES-128) specified in PDF standards. Passwords derive cryptographic keys via standard PBKDF2 hashing routines.
User (Open) vs Owner (Permissions) Passwords
User passwords require authentication simply to view or decrypt the document. Owner passwords enforce restrictions on printing, content copying, and annotation modification.
No Backdoor Policy
Because the encryption standard is mathematically robust, forgotten passwords cannot be bypassed or recovered by PDFSimplify or any third party.
- •Always keep a secure record of your password; encrypted files cannot be opened without the key.
- •Local encryption prevents password transmission over the internet.
- •Supported by standard PDF readers including Adobe Acrobat, Apple Preview, and modern web browsers.
Frequently Asked Questions
Can PDFSimplify recover my password if I lose it?↓
No. Because everything runs strictly in your browser without accounts or servers, we never see or store your password.
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Related Guides
How to Password Protect and Encrypt a PDF with AES-256
Secure confidential documents with military-grade encryption and configurable permissions in your browser.
How to Unlock a Password-Protected PDF (When You Know the Password)
Permanently remove password encryption from documents you have authorized access to.